A review of epoxy products, and their suitability for Glass Bedding rifles.
| Product | Consistancy | Upside | DownSide | Kit |
|---|---|---|---|---|
| Acraglas | Syrup | General Utility | Runny | Yes |
| Acraglas Gel | Gel | Not runny | N/A | Yes |
| Glasbed | Gel | Easy Mix | Wastage | Yes |
| SteelBed | Putty | Strength | Expensive | Yes |
| MicroSight's MicroBed | Creamy Putty | Easy Mix | Dark pre-mix color | No |
| DevCon Plastic Steel | Putty | Not Runny, strong | N/A | No |
| Travaco Marine-Tex | Putty | Not Runny, Price | N/A | Yes* |
There are several good web pages on glass bedding rifles for hobbyists (like this one, this one and this one). The late great Gale McMillan wrote this page on glass bedding at my request, which I formatted in HTML and got him to proof-read. This page is dedicated to him and his contributions to our country and our sport.
Rather than duplicate the instructions, I thought it best to describe what is available to use. When I decided to do the first one myself, my biggest problem was not what to do, gluing the action in permanently, etc. It was chosing which bedding compound to start with!
Alas, I can't show you my first bedding job, as it was replaced by a much better effort by my gunsmith. I used AcraGlas and forgot to mix in the glass floc. I got the color match to the light colored stock perfect, but the result was completely see-through. The only real problem with it is that it was rather thin, and had some voids (air bubbles). In a low recoil rifle, though, it worked fine. The air bubbles came from the AcraGlas running out the screw holes. When I had him refinish and shorten the stock the bedding magically got replaced at the same time. I suppose he felt it necessary. :)
Glass bedding gets its name from two terms, Fiber Glass and rifle bedding. The former is the stuff that Chevy Corvette body panels are made of. The latter describes the method or contact area that a barreled action has with the stock that holds it.
Fiber Glass is just epoxy resin reinforced by woven sheets of glass fiber. The result is something stronger than either material alone. Some people think that adding glass flocking, atomized steel, or other materials to epoxy doesn't strengthen it. I guess they think that rubber tires would be better off without steel belts, or Corvette body panels without the glass fiber. For the technically minded, the softer media simply has a greater strength of adhesion than cohesion.
In putting together this page, I have stuck with products that have been used successfully by many gunsmiths and hobbyists. There might be many more suitable products out there, and some unsuitable ones as well. Once you are familiar with the old favorites, you will have a basis for comparison.
Before Epoxy Resins became commonly used in the 1960's, there were all manner of bedding techniques, all of them rather unsatisfactory. The militaries of the world usually used a metal bedding block behind the recoil lug to prevent the wood setting back, and sometimes a loose collar or pillar around the rear guard screw to prevent wood compression from over-tightening of the screws.
High end custom sporting rifles had carefully inletted stocks that form-fit the actions laid in them. The idea was to spread the recoil force over as large an area as possible. These were used in conjunction with a metal bedding block behind the recoil lug. Some of these were held in place with a screw and end nuts drilled clear through both sides of the stock, military style. Sometimes the end nuts were hidden behind wood caps.
The amount of effort to inlet a stock that carefully is staggering. It required thousands of refits using a greasy compound that showed where the rifle was making contact (bedding) and where it was not. The high spots were carefully taken down a sliver at a time until near-100% contact was achieved.
A military bedding system was considered successful if it prevented the tang from splitting after heavy use, and it didn't work loose when the rifle was fired overheated. For the military, the term "accuracy" in reference to bedding simply meant that a rifle's level of accuracy wouldn't get any worse than it already was due to loosening bedding.
A military bedding block driven back into the wood by severe use. Notice how the wood overlaps it.
The metal bedding block created as many problems as it solved. If it was much taller than the recoil lug, it would try to turn about its mounted axis. If it was the same height it would present not much more surface area to the wood than the recoil lug would!
Competition rifles were particularly challenging. Their high rate of use caused just about any system to work lose. Conventional bedding was combined with animal glues or rosin for temporary glue-in bedding. Split tangs, new bedding blocks and occasional restocking was accepted as the price to pay for high performance centerfire cartridges.
Military rifles turned into sporters were particularly hard to bed due to the very small recoil lugs. Later commercial bolt action rifles have larger recoil lugs. This solves the wood compression problem by increasing the surface area against the wood. However it didn't solve the shifting problem, as the increased leverage of the longer lugs increases the likelihood that uneven bearing of the lug against the stock's recoil shoulder will pivot the barrelled action, causing stringing.
The Brits opted out of the recoil lug altogether and went with a shotgun-style seperate buttstock. This solved one set of problems and created another. It provided greater production yeilds in a resource-poor island nation, because any one wooden stock piece only had to be half as long. If the wood buttstock sets back, it is still secure in the cup and only needs to be tightened. However it can still shift, which leads to vertical stringing.
All of these problems can be addressed with epoxy-based bedding. Nowadays, a home based hobbyist can achieve a better, more accurate bedding job than the finest craftsman of 50 years ago. Careful inletting need only be done near the edges where wood-metal fit is apparent to the observer. The rest can be hogged-out oversized and filled with reinforced epoxy.
The good news is, there are lots of products that will do a good job in glass bedding your rifle. I'll go over them in no particular order.
Photo Credit: Clark Magnuson
The original gunsmith-packaged epoxy resin, AcraGlas comes with glass fiber flocking, mixing (lollipop) stick, black and brown dye packets, paper medical mixing cups, 2-3/4 ounces of Epoxy, and a blue release agent. The release agent forms a film that prevents gluing the action in, but is thin enough to allow a form-fit result.
The two primary complaints about AcraGlas is its non-inutuitive four to one mixing ratio, and how thin and runny it is. The instructions warn about not adding additional hardener over 1:4, as it will give much poorer results. I took that to mean it was better to err on the side of little excess resin, rather than excess hardener. The result was several batches that took 24 to 48 hours to harden.
It turns out they were just trying to keep people from doubling the amount of hardener, which will definitely ruin a batch. The best advice is to try to get it exactly right, and then put a drop or two of extra hardener in. AcraGlas is fairly critical in its mixing ratio, which has caused some to give up on it (and me to consider doing so).
You know when you get the Acraglas mix right. After about 20 minutes, it will heat up and kick over (harden) rather dramatically. It'll get so hot you won't be able to hold the mixing cup in your hands. Epoxies with more fillers (like AcraGlas Gel) aren't so obvious. Small batches don't reach that point of thermal runaway so easily, and can be helped along with an incandescent light bulb placed several inches away.
As for being thin and runny, mixing in the floc or other reinforcement makes it into a thicker syrup, but won't stop it from following gravity out the bottom of your stock. Its liquidity is an asset if you are trying to work it into small cracks for repairing splits in wood. Brownell's also claims that it soaks into and strengthens wood, provided you rough-up the surface first. Sounds good to me. It also allows some unorthodox methods for application, like this one on Steve Wagner's most excellent Turkish Mauser pages. When preparing to glass bed a stock with AcraGlas, the best advice is to dam-up all avenues of escape out the bottom with clay or wax.
Another complaint about Acraglas is the number of air bubbles it seems to grab when mixing. I think all epoxy mixes have bubbles, they are just easier to see in the translucent AcraGlas. As it is thin stuff, most of these will perculate up before it sets. It is good to let this happen before installing the action. If it happens after the action is installed, they may make it all the way out, or they may get trapped against a flat-bottomed reciever. In this case, the voids left are easy to fill with a later small mix of the same stuff, and so should not engender too much bitter complaining.
If only very small amounts of the dye packs are used, the result is transparent, or translucent if enough glass flocking is added. By the time some amount of opaqueness (is that a word?) is achieved, the coloration is rather dark and may not match a lighter colored wood. Whether this is good or not depends on your wood or what you are trying to do. When repairing a crack, a little translucence is probably better than a dark, dark line. If the crack exactly follows the grain, maybe a dark line isn't so bad.
While Acraglas may seem expensive per ounce, it is pure resin and therefore ideal if you want to experiment with your own reinforcement media. The Gels and putties already have some reinforcement mixed in, which limits the amount you can practically add.
Brownell's Acraglas Gel
Unlike Acraglas, Acraglas Gel doesn't heat up and kick over. It takes longer to set up, several hours, but can be speeded-up by warming with an incandescent reading lamp.
Both AcraGlas and AcraGlas gel can be mixed with powdered aluminum, bronze, steel or stainless steel. Since AcraGlas Gel is already cut with Nylon, I would limit the amount of other reinforcement added to just what is needed for a good color match. Don't pay Brownell's ridiculous prices for atomized metal, even if you have the discount. Get a pound for half what 12 ounces cost here instead.
All three Brownell's packages are a good value and will do a good job. Curiously all of them are available cheaper from anywhere but Brownell's. AcraGlas Gel is also available in both small and large ready-mix packs singly or in quantity. There is not much savings over the kits unless you have access to Brownell's business discount.
Brownell's GlasBed
Brownell's makes two packagings of the same Nylon-reinforced Epoxy product, AcraGlas Gel and GlasBed. GlasBed contains a 2 fluid ounce ready-mix baggie of AcraGlas Gel resin and hardener. The color is pre-mixed and your (pre-purchase) choices are Brown or Black. It is cheaper than the other Acraglas products and comes with sandpaper (a nice touch), instructions, tongue depressors, release agent, and a large swab.
To mix, you simply remove the divider from the plastic baggie and knead the two halves together. One advantage of the Glasbed pre-mix pack is that you get little to no air bubbles in the mix. The most obvious advantage is you can't get the mix wrong. You pull the divider between the two sides of the bag and knead, that's it. A limitation is that you are stuck with the pre-mixed color. The only real disadvantage to the packaging is you have to mix all the epoxy at once, so you will probably have a lot left over.
Once the pack is mixed, you must use all the epoxy or throw the remainder away. It will really do two guns at once. When I first used it, I wasted most of it. It is really stressful to do one gun, especially the first time, let alone two at once. It is a couple of dollars cheaper than the other Brownell's kits, so some waste is tolerable.
GlasBed appears a bit misnamed, as it has the same Nylon-based reinforcement additive as AcraGlas Gel, and both lack the add-in glass fiber floc pack. If you are generally handy but have trouble getting the mix right, GlasBed might be for you.
In addition to these there is SteelBed, which is Acraglas with atomized (powdered) steel. This makes a very hard bed that will dull steel cutting tools, and is intended for competition guns and elephant rifles that take a lot of use and recoil abuse.
I've never felt the need to use SteelBed, so I can't comment on it, other than to say it is expensive, like about $25 for 3 ounces. If you have access to atomized metals (or buy them separately from Bownell's), you can mix them yourself with the standard AcgraGlas product. They claim SteelBed has more atomized stainless steel then competing products. It all sounds great to me, but it only seems necessary for the most problematic, high-recoil, high-use rifles.
MicroSight MicroBed
Another product worth mentioning is MicroSight's MicroBed. It is a 3 ounce, two toothpaste tube package in a brown cardboard box. The mix is one-to-one. One tube has red paste and the other black, and the result is a very dark brown color. I haven't bedded a rifle with it but I have used it for stock repair. It does a good job. It sands well (with the usual caveat). It is not quite putty, but is more paste-like than AcraGlas Gel and useful for filling gouges or building up low spots and edges on the stock. The color works well as long as you are working with dark wood. It is opaque (unless spread very, very thin). Acraglas products (except for Glasbed and SteelBed) have more flexibility in the color mix, but can turn out somewhat translucent if a light shade is desired.
MicroBed comes with no release agent. They recommend using several coats of a paste wax. (I suggest leaving the top coat of wax in the white, that is, don't buff it down to a high shine or any shine. Just leave it frosty (but not thick or built-up) when it dries.)
I find myself using MicroBed often for utility work, because of the easy 1:1 mix ratio, and the squeeze tubes make it easy to mix small amounts without waste.
Probably the best bedding job in a rifle I have is by my gunsmith, I suspect he uses DevCon Plastic Steel Putty. It is grey and doesn't match anything. Since it is so professionally done, none of it is visible at all when mounted. Since I'm not at that level yet, I try to take a stab at color match. If some of the bedding is visible, at least it won't stand out so much.
DevCon Plastic Steel comes in both liquid and putty forms. Most rifle bedders prefer the putty. It contains atomized steel reinforcement like SteelBed but costs a little less, but you get one pound instead of 3 ounces. I haven't used it myself. I like to try new stuff, but with all this epoxy lying around right now, I'd have to buy several more rifles to justify purchasing some DevCon.
DevCon does well in the value department. At the time of this writing, Enco has it for $21.24 for 16 oz. It is also available in a two tube package for about $3.00. In the larger quantity that's only about $1.33 per oz. of reinforced resin.
ITW Philadelphia Resins makes Travaco brand Marine-Tex. It comes in 2 ounce and 14.5 ounce containers, and is the most reasonably priced of all these mentioned. It has a very thick putty consistancy, comes in gray and white, and has a challenging five to one mixing ratio by volume (6.3:1 by weight). Mix tolerance is given as 10%, with the usual warning that overages of hardener will compromise strength.
Marine-Tex Gray is a favorite of many professional gunsmiths. While DevCon Plastic Steel is marketed towards professional maintenance workers and industry, ITW markets primarily to boaters, and then the fix-it crowd in general. ITW recommends the gray (really metallic black) color product for metallic repairs. It also claims to bond dissimilar metals without galvanic corrosion problems.
Since the primary market of Marine-Tex White is boaters repairing fiberglass hulled boats, I would suspect that Marine-Tex White might be especially felicitous in skin bedding, repairing and accesorizing fiberglass stocks. The higher metal content of Marine-Tex Gray would give it the nod for bedding. The difference is in expansion/flex characteristics versus resistance to impact. White better matches fiberglass stock flexibility, while Gray is less likely to compress under recoil.
I have used Marine-Tex Gray to bed one rifle so far, and it did a good
job. It was mixed at 65 degrees F but left to cure under a 40W lightbulb
less than a foot away. I did not notice a thermal reaction within an
hour, but 12 hours later it was completely set-up (full curing takes a
bit longer). It is so thick that it did not run or settle at all. When
used for bedding one must make sure low spots are filled, or they will
be voids when finished. You can't rely on gravity to make it settle to
the bottom or level-out.
If you strike out on your own and try another epoxy product, I can only give you some general advice. Avoid the very quick-setting epoxies, as they lack the strength of the ones that set and cure slowly. Avoid outdoor, concrete fill, or construction type epoxies too. These have reinforcement additives that are compressable, to better handle shrinkage and expansion due to freezing water, hot summer days, etc. While more flexible they are more likely to be beaten down by recoil. Steel barreled actions expand only trivially when hot, and well-seasoned wood, properly sealed and glass bedded, is only going to swell a tiny amount on hot humid days. The purpose of the glass bedding is to minimize such changes, not go along with them.
Automotive epoxies come in at least two varieties. One is the body panel fill type, which is full of cheap, light filler. The other is the large cans of epoxy and resin intended to be used with fiberglass cloth for layup. With this stuff you could make a whole rifle stock from scratch. It probably wouldn't be bad for glass bedding, but you would want to add some kind of reinforcement, either fiberglass floc, atomized steel or aluminum, etc. As for consistancy, it tends to be on the runny side. Gallon for gallon it may be cheaper in unit price than any other epoxy, but it is hard to utilize such large quantities within the shelf life.
JB Weld is popular with some hobbyists, but I've never seen or heard of any professional gunsmiths using it for bedding (everything else, but not bedding). The properties given on their web page show it to be comparable in shear strength and tensile strength to Marine-Tex Gray, but it has better heat resistance than any other epoxy product (that gives out specs). It has an easy 1:1 mix ratio and a typical 30 minute work time.
If you get the Brownell's catalog, you'll see they make a dizzying array of Acra-type epoxy products: Acra-Quick, Acra-Quick Gels, Acra-20, Acra-Bed and Acra-Weld. The first three epoxies are double-plunger packages for general repair use, and the first two of those are quick-setting. The last two come in toothpaste tubes. Acra-Bed seems to exist only to duplicate MicroBed. It comes pre-colored but in a choice of Brown or Black. I have no idea what differentiates Acra-Weld. It only seems to exist to compete with JB Weld.
The only one of these I've used is Acra-20. I chose Acra-20 over Acra-Quick because it's 15 minute working time sounded more stress-free than Acra-Quick's 3 minute time. I could never get it to mix right, and usually just ended up with a mess. Now that I've tried MicroBed I understand why people prefer the toothpaste tubes over the double plunger thingies. All the Brownell's Acra brand epoxy products except Acra-Bed can also be colored using Brownell's dies (for a small extra fee of course).
DevCon and its competitors make other consumer epoxies. Don't assume to "2-ton" or "Five Minute" stuff at the local store will do a good job as a rifle bed. I wouldn't use any quick-setting epoxy for bedding the recoil shoulder. They work well for stock repairs, filling gaps hidden in the forearm, etc.
If you have to buy some epoxy for the job, might as well get DevCon Plastic Steel or Marine-Tex, as they don't cost that much for what you get, and you will start with a proven product. Both can be had in smaller two-tube varieties for about US$3.00. If you are cheap, have a cheap gun, and already have some epoxy product half-used on your shelf, well, who am I to stop you?
When using a cheap, fast or suspect epoxy, you want to rely on it for positioning and filling more than strength. If your rifle bed is already sufficiently strong, you'll most likely still experience an increase in accuracy. There are many ways to get the wooden rifle bed sufficiently strong, including metal screws, sections of pipe or compressed air fittings as pillars, etc. If these bear the brunt of the recoil and are firm against the wood, and the epoxy just glues it all together and prevents side-to-side shifting, you'll probably have a successful bedding job.
If you are bedding a military rifle in its original stock which retains the metal bedding block, you might get away with some cheaper epoxies. You will need to get the epoxy under the block, and around the end nuts, etc. Just keep in mind that if it doesn't work out, it is hard to remove from between the block, through pin, and stock. Like, really, really hard.
Beware of false economies. It only takes one ounce or less to bed the average stock. You may get 16 ounces or more for the same price as a 3 or 4 ounces of quality epoxy. Unless you have 16 rifles ready for glass bedding, you may not be able to use your remainder before the 4-5 year shelf life runs out.
If you are dealing with a straight-up resin and hardner, you can improve its strength by adding atomized stainless steel, like from www.artstuf.com. Stainless Steel, Aluminum, and other metal powders are available. However if you are using a cheap, bulky putty epoxy from the home supply superstore, it has already been cut with chopped nylon, shredded wheat, whatever, and that limits the amount you can improve it.
The first generation of epoxy glass bedding did well for its time, but if you have an old glass bedded rifle, you may find the bedding is past its prime. Cracking, "sugaring", or crumbling is not uncommon.
A good glass bedding job with a modern product on a typical hunting rifle should last a lifetime. If the rifle is high recoil, or used weekly for practice and competition, it should be considered a long-term maintenance item, like brakes or tires on a car. You don't have to change them every time you change the oil, but you'd better change them before they wear out completely.
Replacing existing glass bedding is not hard. You just need a Dremel (Foredom, or other die grinder type tool), a cutting bit, and a dust mask. Hog it out until you see wood. If it is in a fiberglass stock, it might be useful to not get an exact color match so you can sort it out later. The most difficult removal is where there are metal pieces embedded in the epoxy, such as in an old-style military bolt action, or if wire was used to reinforce the bed. So, beware if removing someone else's bedding job. Who knows what's hiding in there!
Cheap or unreinforced epoxy will eventually get beaten back at the recoil shoulder by a .30-06 class rifle. If you elected not to leave space in front of the recoil lug, repeatedly wrenching the action out of the tight bedding will loosen it up via mechanical friction and wear. If you disassemble your rifle a lot, it may be better to leave space there, so the bedding is only "tight" in the recoil bearing surfaces.
Cheap plastic stocks and some synthetic stocks will not adhere well to epoxy. In these cases you can still get a good bedding job done. You just need to establish a mechanical lock to be secure. I drew this picture to help explain. Drilling lots of holes and deep gouges helps. Here is a link where a manufacturer describes how to bed their molded plastic stock. It's not pretty. You need either an automotive fiberglass resin kit (that can flex with the stock) or SteelBed (which is strong enough to reinforce itself), plus rebar (er, wire and brads). Once that is done, the flexible stock is just along for the ride.
Generally unused epoxy shelf life runs 4-5 years. While the shelf life of most epoxies is listed on the packaging, instructions, or maybe web site, most consumer epoxy products are not marked with a manufacturing date (at least not obviously). You also have to consider how long it has been sitting at the store you bought it in. Shelf life can also be reduced by wide variations in temperature and poorly sealing lids.
The best I can figure is to mark each package with the purchase date. This allows me to use oldest first, and reconsider what to use when the date marked is getting around 4 years old.Declaring one product better than another in the area of coloration is impossible because there are so many different requirements for color matching. Light wood versus dark, figured versus plain, laminates versus synthetic in every stripe and description, they all demand special treatment. Brownell's suggests that a lighter color is least likely to conflict with grain in in a wooden stock crack repair. They sell a white "toner" in addition to cups of Green, Brown and Black dye. The white toner is to lighten the other colors instead of make a pure white mix. A black and a brown die packet come in each package of AcraGlas. This is probably what is needed to get an opaque mix that is not too dark. If you have access to titanium dioxide you can just use that. Marine-Tex White is already opaque and white, can be dyed various colors. The metal filled epoxies (Marine-Tex Gray, SteelBed, and DevCon Steel) are going to be dark and opaque no matter what. They can be tinted in one color direction or another, but don't expect to be able to match a lighter color.
How do you prevent epoxy from overflowing everywhere when you drop in the barreled action? I don't. I put paper masking tape all over the stock anywhere near the bedded areas. Then I put release agent over the paper tape (if you put it right on the wood finish, it might dissolve the finish). I use lots of epoxy, dam up the bottom with modeling clay, and then I don't have to worry about voids. When the action goes in, it comes out every seam, and I wipe off the excess with a lollipop stick.
An action riding high in the stock is a typical mistake. It can be avoided by test-fitting the barreled action several times before pouring the epoxy. Do it after any tape has been placed in the action and all dams and clay fills have been made in the stock, but before you put the release agent on the action. Clay tends to strip off the release agent.
Avoid mechanical locks on the action and barrel. This would be any place where epoxy can wrap around or intrude enough to grab something, even if that something is covered in release agent. Examples include any holes, grooves, pits, ripples, proofs, acceptance stamps or rough finish. Pack all of these with clay before mixing epoxy. Another gotcha is round receivers deeply inletted into their stocks. If the epoxy reaches above the midpoint of the receiver it will hold it in place, release agent or no.
Utilize mechanical locks to keep the bedding in place in the stock inletting. Drill holes in the stock at different angles in places to give the epoxy plenty of places to grab and hold, and to increase the surface area of the bond.
Wood should be roughed-up with sandpaper to increase adherence. Gouges cut in the wood will increase the surface area of the bond and make the whole stronger. If it is not a new stock and the inletting is not sealed, it probably needs to be degreased. Finally, a bad mix ratio will result in something that can't be saved.
Skin bedding can also tell you if the bedding system is engaging the receiver correctly. There should be some areas where the receiver lug and/or tang touch the stock bedding, and the epoxy is only skin thick or is practically eliminated by tightening the guard screws.
Inevitably after mixing a pot of epoxy and using it for its intended purpose, you have more than half left over. The best use I've found for the excess is fixing hammer heads on handles. Mallets, axes, hatchets, you name it, there's always one with a wobbly head.
What is a release agent, anyway? It is simply some kind of film or layer that prevents epoxy from permanently gluing itself until things. Brownell's includes their release agent with their products. It is 100% effective in preventing bonding, as long as you cover 100% of anything touching the epoxy. It dries to form a film that can be peeled off once the job is done. Being a liquid, it can build up or pool on application, and while very thin when properly applied, is still a bit thicker than using a paste wax. Brownell's release agent is blue, so it is easy to see if you have complete coverage or not.
If you want the ultimate in very tight bedding, a couple of coats of automotive or floor paste wax (no silicone products please), buffed out, is as tight as you can get. However, since it dries clear, it is easy to overbuff or miss a spot, and permanently associate your stock and action.
Any usual sandpaper can be used. At first you'll be disappointed by the finish of sanded epxoy, it will look white and frosty. Just wet it with whatever fluid is appropriate, linseed oil, gun oil, whatever. It will settle down to its base color. Sanding it with a finer grade grit will help. Matching or finding the right grit in order to match the wood finish also helps. You will have to do this by experimentation, sand, wet repeat until you get a good match. This is assuming the expoxy is visible and you are trying to blend it in. If it is concealed with the rifle assembled, forget about it.
I particularly like the no-fill sandpaper from Jantz Supply. It is made in Canada and loads (gets clogged up) slower and unloads faster then any 3M product I've used. To unload, get one of those big natural rubber erasers made for that purpose. I use them even for hand sanding. Fortunately that is available from those otherwise useless home superstores.
Whiting, or Calcium Carbonate CaCO3, is used to remove gun (petroleum) oils from oil-soaked wood before applying bedding. Whiting can be bought here, which is also a good source for Titanium Dioxide, Burnt Umber and Yellow Ochre.
Lollipop sticks for mixing can be had at your local hobby and craft store. You'll probably need more than the two you get in a kit anyway. Modeling clay is essential for building dams to prevent the epoxy running out. Use it also to fill pits and tool marks in the barrelled action to make removal easier. The paper medical measuring cups that come with AcraGlas must be available at Pharmacies; I've been too healthy to check lately. If they are calibrated in cc's they will make measuring those oddball ratios a lot easier.
An alternative, or supplement to modeling clay is candle wax. It can be dripped down from a burning candle and naturally seeks low spots. I like this approach because it has the same consistancy as freshly mixed epoxy and will run into the same places. If it runs straight out the bottom you know you're not ready yet. Using it is described in MouseMag32's page(dead link). He warns about assembling and disassembling before the epoxy is used (or sets) can mess up the wax; the same is true of clay.
If the stock has other problems that need fixing, before or during a bedding job is a good time to address them. You can find threaded brass rod at the local home superstore or hobby/craft shop. Read this link to find out how to use it with epoxy. Experienced gunsmiths may smile, but this simple repair is an excellent first project for the beginner.
The greatest hazard of glass bedding is permanently attaching your action to your stock. This happens for two reasons; insufficient release agent, and mechanical lock.
If no release agent was used, the only known cure for this is deciding which is worth more, and then using a hammer and chisel on the stock, or a grinder on the action. If you did use the release agent, other hazards include gluing triggers solid, blocking triggers so they do not reset between shots, and gluing in the bottom metal permanently (this can usually be lived-with). There are probably other hazards. I will not be responsible for any actions you take based on the information on this page. If you run into problems, tell me about it and I'll try to point them out here so others can avoid your fate.
If your action and stock won't come apart, here's some tips. Don't panic. There are some things you can try. One is putting the whole thing in a freezer. Metal contracts at a different rate than wood or fiberglass, and can give you the clearance you need. To increase the expansion/contraction effect you can heat the action with a light bulb or hairdryer before freezing.
Another method is tapping on the recoil lug through the front action screw hole. The tang (rear) screw should not be used to drive out the action, as the tang is easy to bend upward. Try to use as large a driving rod as possible, preferrably brass to minimize peening of the steel. If you can thread a headless screw into the front action screw hole, that will better preserve it. If you need to hammer on the front action screw, make sure it is threaded in at least 3 full turns. Anything less and you will just bugger-up the threads of both action and screw.
If you need a handle to pull on, put a scope lapping bar or one inch round stock in the scope rings and use that. Pulling or banging on the scope will just ruin the scope.
Do not simply grab the barrel and pull up as hard as possible. The leverage will permanently spring (warp) the receiver. Try to back-out the tang a little first, and then you can pull on the barrel a little bit.
The best defense is a good offense. Avoid unwanted mechanical locks by making sure everything tapers without dishes or concave areas that will be grabbed and held by the epoxy. Triggers are notorious for this, even when taped over. Put two coats of release agent on everything, well beyond the area being bedded. Pack clay in the action screw holes to prevent all the epoxy from running out. Put tape all over the outside of the stock so any overrun won't harm the finish.
Ken.
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