Has anyone made their own fiberglass style stock?

[TLong]

I've seen people make wood stocks and metal chasis style stocks. My question is has anyone made their own fiberglass/kevlar type stock with any success? If you have, could you please post up some pics and a list of materials used. Thanks.

[BigDaddyKane]

I actually have tried this exact thing. My extended family has rebuilt clasic cars for as long as I can remember. So I have some experience with fiberglass resin's for auto-body sculpting. Last summer I took some angle steel and bent it into a rudimentary shape of a rifle to use as the main support/action framing. Then I used fiberglass screening and resin to pour & shape my own stock. It was quite fun, and a TON of work. However, the end product was far from usable. It was no doubt strong, as it weighed close to 20 LBS. Fiberglass is heavy as all sin but I'm sure the steel frame didn't help. The other thing is... fiberglass, as strong as it is, does not have the greatest "shock" resistance. So with all the recoil, you can expect it to crack. However, I believe this can easily be done using the proper materials....

If I did it over again, I would use some sort of polypropelene, or metal based plastic resin. There are literally dozens of companies that produce plastic resins for movie sets... you know for building a 2000 lb boulder that actually only weights 10 lbs. They make all sorts of consistencies and strengths. There are some plastic foam and/or resins that can hold an adult males weight on them and still be incredibly light. With that in mind... I would take some scrap 2x4's of pine or a solid 4x4. Using a band saw, belt sander, router and hand file, I think I would make a very rough shape of the stock I am trying to build. Use that as the base for creating a mold... then once the mold is made, you can pour a solid reinforced polypropelene rifle stock. Router out the channel for the action and barrel, and have a milled block of aluminum set down for the action.

It is certainly doable, and with the right effort and patience it can defintely be done. But the question is... for all that effort, time and money (expect at least $150-200 in cost)... would you still want to build one? or just buy one?

[TLong]

BigDaddyKane,
Do you have any experience with additives such as microbubbles? I was thinking of adding a 50/50 mixture of the microbubbles to the resin.
Here is my thinking,
Create a mold with plaster-of-paris of just the basic, rough shape.
Use fiberglass mesh/resin on the outside of the plaster to create a hollow "body".
Pour the resin/bubble mix into the cavity I just created and allow that to harden, with an aluminum channel for the forearm where the barrel would go. (Freefloated of course, but have the aluminum as a reinforcement)
Once it hardens, I would then shape the stock to what I want, then re-glass the outside of the stock.
Finally, I would inlet the stock to recieve the barrelled action.
If I have missed anything, or have left anything out, I am open for suggestions.

[JWW123]

a much lighter fill can be made with saw dust from a table saw how ever i would sugest using 2 part flotation foam 4 or 8 pound per sq ft do not use polyester resin as it shrinks EPOXY resin is the only way to go here check on web there are some boat sites and airplane sites that should help you out good luck jw

[TLong]

I was going to.use the epoxy resin as my filler for the mold. West 105 is what i was thinking, are there any better epoxies to look at? Also what about milled fiberglass fibers instead of the microballoons?

[JWW123]

you are looking for a light weight fill milled fibers are too heavy as is micro bollons there is to much surface area around the partical there fore more resin is needed to bond USE FOAM with epoxy any foam will work with polyester the only ones are urthane based all others will melt luck jw

[BigDaddyKane]

The problem you run into with Fiberglass is that if it is not mixed perfectly it can become very hard and almost brittle. I mean, imagine it as actual glass. It can chip and crack and is quite a pain in the ass. So if you have a large caliber rifle the recoil will destroy that thing. If you use the mixture at all it needs to have a significant amount of the fiber screening to go with it. The issue that arises is that fiberglass, although incredibly strong, is also quite heavy. The finish is much different than you would expect for the final outcome for a rifle stock. Like I said, I would look into something more like a urethane expanding foam resin, polycarbonate, or some sort of casting plastic resin. Check out companies like Smooth On, Devcon (yes the bedding compound), or Goldenwest Mfg. You can even google search plastic resins and find a dozen companies that specialize in this sort of thing. There are so many plastic composites that are ridiculously strong with minimal weight. Again, think about the Hollywood movie sets that build a 1,000lb boulder that actually only weighs 20 lbs. Like I said, after having worked with Fiberglass, I don't think I would use it as a filler, or outer layer to my stock after having worked with it.

These plastic resins/compounds are so strong that you wouldn't need any sort of metal framing. However, the aluminum action bedding would certainly be a significant improvement to the stock. I would suggest pouring the stock and allowing it to cure, sanding, carving and getting your shape done. Then, router out the barrel and action channel. You can epoxy bed the aluminum frame into the rifle stock so it is permanently part of the body. There are tons of ways to do it. Let me know what you're thinking. I don't think this is out of reach, you just have to figure out a resin/plastic/compound that has a good strength to weight ratio.

Keep me posted!

[TLong]

Ok guys, here's what I've got so far. I have a plaster block that resembles a stock, (its just flat on all sides). I want to make a mold of that out of something to basically have a negative of the stock. I have some left over 2part hobby foam, (i cant recall the manufacturer, but it expands up to 20x the poured amount.) Is this ok to use as my foam that you guys are referring to? If so, what would you recommend I use to go over the foam? Epoxy resin and fiberglass mat? Just epoxy resin? It really doesnt matter what the color or appearance looks like, because it will be painted; I just want it to be strong enough to handle being used.

[tinkerer]

My suggestion.

Start with a Whidden V Black for your action. Place this in a soft wood (pine, maple, bass, whatever) in the approx final shape. Coat action with release agent and coat rough stock with wet fibergalss (or even carbon fiber/polyester) and place action in and bolt in place. Wait to hard and remove and sand to final dimensions. No fillers needed.

This is how they used to make stocks for silhouettes as weight was a premium.

Your time, your choice.

Larry
Tinkerer

[BigDaddyKane]

If you use any sort of fiberglass/resin you almost certainly need to use a screen or matte. The fibers are actually what give it the strength. Hence... FIBERglass. Without knowing which foam you are using I cannot say whether it would work... usually the ones that expand that much are made up of a significant amount of air. This COULD equate to weakness but not necessarily. BUT, it could mean a very spotty finish... you'd need some sort of filler on the final product anyhow. What you need to do is research the strength of said foam and see how it compares to other materials. THEN... BEFORE BEFORE BEFORE you pour your mold, use this foam in a scrap cardboard box (something small like a gift box) and let it fully cure. Test its strength, see how well you can shape/carve it into something. Get to know what you're working worth before you put that much foam out there, and before you waste your mold.

Also, what caliber is the rifle going to be again? I mean, a .22lr doesn't need the strength that a 300WM does. So it will all vary on your need. Also... pictures speak a thousand words... get some up if you can and I can help point you in some direction. Feel free to private message me as well

T

[TLong]

Ok, Ill try and get some pics up when I start getting underway. The foam I have is made by Alumilite, super foam 320. It is 3lb density foam when cured.
I plan on this stock goin on a 7mmRM, if it is able to handle it.
Here is a crappy pic of my plaster design...it is about 2 inches thick. I left the forearm and butt wide on purpose.

[TLong]

Okay, I made a baseball size ball of the foam in question, and tested it's strength the best I knew how. I squeezed it, threw it against the floor, tried to put my thumb through it, cut it with my knife and took a file to it. How much deformation am I looking for when I squeeze/jam my thumb into it? It filed and cut beautifully.

[JWW123]

none

[BigDaddyKane]

exactly... you dont want ANY sort of leway. If it flexes under your thumb pressure imagine what it will do with 27ft/lbs of energy kicking back from your recoil. Take a hammer to it... put that thing through hell. Try to find it's breaking point. Only then can you know what its limitations are and whether it will withstand a magnum cartridge. Have you handled the HS Precision stocks? They are literally hard as a rock but not terribly heavy by any means. That is what you're looking for.

So you're going to take the foam core and carve it into the approximate shape, then plaster of paris around it to create a mold... then fill said mold with the modeling foam to create the stock... correct?

[TLong]

I did not beat it with a hammer.....yet. But when I would squeeze it or try and dent it with my thumb, it was pretty solid. I will try the hammer trick this evening.
BDK...that's right, for the most part. I am not going to just use the foam by itself. I want to utilize either carbon fiber mat or fiberglass mat on the outside of this modeling foam stock, to add strength and rigidity. The foam will act as my shape and base to lay the cloth onto, and impregnate with epoxy resin.

[BigDaddyKane]

Not that you necessarily need it to withstand a whack from a hammer... but I would rather know what its limitations are prior to building/firing.

May I also add... that when you eventually mate the stock with an action and go to fire... mount it on a durable sled, and tie a string to the trigger... I'd want the first few shots done away from me so that in the event the stock does break... you're not holding it against your face.

The more layers of screen/mat you can use the better... that is literally what will give it its strength. The resin just bonds fibers together.

[JWW123]

make your mold i suggest a 2 part mold split on the vertical you need to be @1/8 to 1/4" smaller than your finished size put mold togeather and pour with foam,after foam has cured unmold and cover with 7to10 oz glass cloth DONOTUSEMAT epoxy resin is the only way to go action area and palm will need @6 layers all others 4 iwould suggest u cut a pc of cloth for action & palm then cut a 2nd pc @1"larger all the way arround bond the 1st pc to foam then bond 2nd cover entire foam blank with 2 layers cloth use a plastic squegee to move epoxy arround u do not want to be resin rich use only enough epoxy to wet out let cure sand off any bumps runs ect. wipe with acetone coat with last 2 layers or cloth and let cure sand and coat with more epoxy resin keep sanding and recoating till smooth when sanding u dont want to sand through cloth sand off resin only for your last coats of resin u can mix some phonalic micro bollons or microsphers i use phonalic stronger u can also use baking soda works ok i would suggest you look ata more solid fill for arround the action than foam recoil needs to be addressed that is why i suggested saw dust non compressive with this you can bed over and it will look good the reason i would not use mat is epoxy willnot melt binders it wont wet out well i use mat only as a fill or to tie old to new glass on the boats i build good luck

[JWW123]

fwiw i would do a fiberglass shell and fill the recoil and palm area with sawdust epoxy mixture butt and forearm with foam butt be shure to put 2 wood dowels to screw recoil pad to jw

[TLong]

Great advice guys. Thank you. BDK, I did actually whack the foam with a hammer a few times, and it dented in the middle, more of a compression really. It didn't shatter, crack or have any signs of structural damage, other than being compressed.
I had completely forgotten about the recoil pad area, until JWW123 said to add some dowels.
Still in the planning stages, but I think I like where it's going, and it seems do-able.

[BigDaddyKane]

Any updates on the stock build?

[jraney]

what kind of foam would you use, and where do you get it? also where can you get really thin fiberglass at a reasonable price?

[Westcliffe01]

Guys, for one off type jobs in composite without making a bunch of molds read this book: http://www.aircraftspruce.com/catalo...s/moldless.php Cost just over $16.


The guy that invented the process used it to build several record breaking airplanes, which he sold plans for until the lawsuits from idiots became too much. Several thousand of these aircraft are meanwhile flying.

The first thing is to understand the loads and with that knowledge design the structure. Areas that have to take impact and high point loads will be built up with multiple laminations of glass fiber over a foam core. The glass layups take the tensile and compressive loads and the foam only spaces the 2 "flanges" the right distance apart. One of the tasks in the manual is making a "stick" about 2' Wide and 1/2" thick with a foam core and layups on both sides which after curing will support the builders weight when balanced on a broom handle. Even when the builder jumps up and down !! By comparison, a rifle stock is a much bigger item and does not have to endure nearly the same kinds of loads.

The book covers the different types of cloth and resin and stresses technique severely. It doesn't teach you to design a structure, but how to get the right glass/resin ratio, to keep the fibers straight (since they can't carry load otherwise) etc etc.

It is a fair amount of work, but the amount of material in a stock is not that great and the hardest part is the final finish. Most consumer type resins are not UV stabilized, so they have to painted adequately to retain their properties.