Home Forums Hunting & Shooting Gunsmithing More epoxy questions????

What is the best stuff for building up a Fiberglass stock? I need to relocate a bolt notch and reshape/locate a mag port. Which would you pick to do structural stuff. Build a plam swell, raise a check piece or comb ect. I think a putty type would be the best, spelled easiest to work with. What will hold and not break or flake off.

Note I am talking Fiberglass stocks, Banser McMillian ect. Not ram line or other injection molded plastics.

I would use sheet fiberglass like you would on a boat or a surf board...but the first thing I would do is call the techs at McMillan and ask their advice.

West Marine, or any good boating supply store, carries patch kits for boats that should have more than enough material to do what you are talking about.

I agree with RickB, doing as he says will probably be the easiest way to go. The type of epoxy you use to wet out the fiber probably isn't that critical, but you will want one that has a fairly long (1-2 hour minimum) working time since it might take you a while to get your part in place. Also, remember that the surface preparation of the part you're trying to bond to is probably going to be the most critical part of the job, so take special care here. Most epoxy/fiberglass composites can be easily sanded or machined, but the glass is very abrasive so it will wear on your tool or sandpaper more quickly. Take care to wear a respirator when you're doing that since inhaling those small fiberglass particle is not particulary healthy!
Test

Marine Tex....

MIGHTY PUTTY

Sorry
The devil and Billy Mays made me do it!

Mighty putty..

"Bonds wood to metal
Metal to glass"
I wish Mays would use it
To stuff up his ...

OH how I hate loud pitch men!

Many moons ago when I built radio controlled airplanes we mixed a fine powder called microballoons with slow-curing epoxy. The more powder you use will make the epoxy have a paste or putty consistancy and is easier it is to sand it to a contour. Marine stores carry microballoons. You can epoxy over a polyester resin surface but you can't use polyester resin over an epoxy covered surface.

Glass microballoons are used in aviation to make syntactic foam which is microballoons (or other light weight material) and a resin system. Adding microballoons results in a thicker and lighter material the but the mixture is not very strong, relatively speaking. Strength varies depending on the resin system used, type of microballoon or other aggregate, and epoxy/balloon ratio. It would not be good for rifle bedding.

Edit ----- Read the post, stupid ------

Microballoons and epoxy make a fine filler and that's it's primary application in aviation. Lighter than Bondo (polyester resin and mostly talc). In fact it's my favorite filler when working with laminates. If you use it plan on between 2:1 and 4:1 balloons/epoxy by volume. Wear a dust mask, the balloons float like dust and will do you no good.

Bondo.