Re: Filling the butt end of a polymer stock?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: SomeOtherGuy</div><div class="ubbcode-body">So I took the buttpad off to see what I would find, and it was hollow just as expected - except for a large piece of styrofoam taking up most of the space! Yeah, cheap styrofoam, clearly cut from a block outside the stock and pushed in there. Why bother? Why couldn't they have just poured something in place?
Anyway, seeing that I think I will try the two-part urethane foam. Jrm850, any more pointers on that? I'm inclined to use one of the heavier grades of foam, probably 8lb, to get the maximum stiffness and improvement in feel. </div></div>
I would fill the cavity with water until full, then pour that water in a measuring cup so we can get an idea of the exact volume. This will help avoid mixing too much and give us an idea of the added weight. I have a chunk of the 5lb in front of me but I'm having a hard time finding words to convey the material properties. I can only dig my fingernail in it about .030" so it's much stiffer than standard packaging grade polystyrene. This chunk is a 3" cylinder and I can stand on it with very minor deformation. I weigh 225. Obviously the heavier the better for your major requirements. I would come up with a number for whatever additional weight you can stand and pick a density to meet that number.
this stuff will stick to just about anything so make sure you mask off your entire stock before filling. Use a much bigger cup than you think you will need when mixing. Mix it fast and thoroughly. You have a very short pot life before it starts to grow. I fabricated a small mixer paddle to use in a coordless impact wrench. (Spins faster than the drill) I would mix a small batch and pour it into a cup for practice just so you know what you are dealing with. You can trim it with a knife before it fully cures but it's tough to trim after it's cured. A sureform file makes quick work of the lower densities when you go to remove the muffin top.