Anyone know if mono-style expanding foam has problems with fibreglass resin? I'm thinking about about how to improve crappy factory injection-moulded stocks on the cheap. I figure I might try filling the forend in with expanding foam, hogging out the barrel channel, and wrapping the whole forend in a fibreglass mat. I figure (hope) this will go a long way toward increasing rigidity without increasing weight too much.
Foam/Resin compatibility
- Thread starter prosper
- Start date
Injected stocks
The problem with the injected plastic type stocks is that glass does not form a good bond to it as it exists. A solution I use to steady up the fore ends is to really chew up the interior of the stock so that subsequent glass bedding can form a strong mechanical lock on the stock. Some stocks have such large voids in them that adding that much bedding compound adds too much weight. I use sections of broken graphite fishing rods (hollow) and golf club shafts and cut them to exact length so they fit tightly in the voids. Then a good glass bedding compound is used to fill remaining unwanted space while bedding the channel in the normal manner. This will make the forend very rigid but you will gain several ounces in stock weight.
The problem with the injected plastic type stocks is that glass does not form a good bond to it as it exists. A solution I use to steady up the fore ends is to really chew up the interior of the stock so that subsequent glass bedding can form a strong mechanical lock on the stock. Some stocks have such large voids in them that adding that much bedding compound adds too much weight. I use sections of broken graphite fishing rods (hollow) and golf club shafts and cut them to exact length so they fit tightly in the voids. Then a good glass bedding compound is used to fill remaining unwanted space while bedding the channel in the normal manner. This will make the forend very rigid but you will gain several ounces in stock weight.
TERMINATOR101CA
CGN Ultra frequent flyer
- Location
- TORONTO, CANADA
Check the contents of the expanding foam, if it contains any styrene or such the resin will react with it and melt it on the spot.
Most expanding foam insulation will not be affected by polyester resin. I use it all the time to make stock modifications and to build plugs for creating custom stocks.
A friends father is a boat builder and they use it for making quick plugs to make molds.
Polyester resins will bond with the injection molded stocks better than epoxy, but as stocker said it works best when you rough up the surface to promote a good mechanical lock.
A friends father is a boat builder and they use it for making quick plugs to make molds.
Polyester resins will bond with the injection molded stocks better than epoxy, but as stocker said it works best when you rough up the surface to promote a good mechanical lock.
- Location
- Edmonton, AB
Brad, if you want/need help with the fiberglass work, I've messed around with it a couple of times... been a few years, but I think I remember what to do 
Seems to me I read on one of the threads that the tupperware stocks need to be seared before good bonding can take place, someone got this off a canoe repair site, from the manufacturer. I haven't tried this yet, but I plan to when I have a little spare time. I've used the hog it out and glass everything method with some success, but it isn't pretty. - dan
Mystic Precision
CGN Ultra frequent flyer
- Location
- Summerland, BC
how about shoot?
Jerry
Jerry
