Jason,
I asked a similar question a couple of years ago. Although you have already gotten farther than I have in actually trying the two part foam, I'll share some good information that I was provided then to save a couple of the guys some typing time.
Hope this helps,
Scott
(ps: I have made a bunch of EPS decoys from the molds)
Two-part foam decoy info request
Posted by Scott Farris
Time Posted: March 9, 2006 at 4:40 p.m.
The mold discussion below got me scheming. I’ve been a bit slow about trying the two part foams. I’ve had decent luck with the EPS but the thought of committing to that level of effort this year when I already have 1 or 2 hundred EPS bodies with heads kicking around is turning me off. I do however have a new (to me) brant mold set, a small puddle duck mold (teal?) and a couple of new head molds like GE’s that I want to produce a couple of dozen blocks each with. The two-part foam sounds like the way to go but I have a few questions.
My molds are older design set up for EPS. Do I have to modify them to use either the 4 or 5 lb foam? I’ve heard drilling vent holes may be necessary but I would rather keep this rather substantial investment in molds in the best shape possible. Along the same line, any truth to the stories of the two-part foam damaging the aluminum molds? I’m certainly willing to carefully measure the volume of the molds and mix the correct quantity of foam to fill it. I’ve also heard that the 8#/cft foam is superior to the less dense foam for the heads. Any experience?
The working time for the foam before it starts to expand is listed at 45 sec. But I didn’t get a feeling how long it needs to be left in the mold to cure. Is this a 30 min cycle time on a mold? Hour? Longer? While boiling, the cycle time is roughly an hour but I’ve got 3 or 4 bodies going and at least as many heads going all at once, so I normally end up with around 33 - 36 bodies and heads in a day. (One decoy mold set would cycle faster but you would sit on your hands a lot as the molds boil then cool off). Never open an EPS mold before cool or the foam will continue to expand unrestrained and crack your decoy.
All Two-part foam tips, instructions and tidbits greatly appreciated.
Charlie & Titan if this is an all day or two event, come on down and use the other molds. I’ve got three diver molds, a puddle duck and a goose mold in addition to the ones I need to use.
Posted by Sab
Time Posted: March 9, 2006 at 4:51 p.m.
In Reply to:
Two-part foam decoy info request posted by Scott Farris on March 9, 2006 at 4:40 p.m.
OK here we go.... I use the 2 part foam exclusively. I use 4# foam. I have about 45 seconds to mix it up but even after I pour it into the mold I still have about 15-25 seconds to put the c-clamps on it to hold the two halfs of the mold together before the foam rises to where I can't work with it. I use the c-clamps because it's faster and easier than using the screws that come with them. I have drilled a small(between 1/8 and 1/4 inch hole on the "back" of the duck to give the excess gas then foam a place to go. I never had a hole until the last 3 dozen I made and the back or wings always got "shiney" and kind of un finished. I use 9 ounce plastic disposable cups and put 9 oz of part a and 9 oz of part b. After I clamp it together and the excess foam comes out the hole I wait an additional 10 minutes. Total time for 1 decoy is 25-30 minutes. Any questions just e-mail me
Posted by R.A. Coleman
Time Posted: March 9, 2006 at 9:58 p.m.
Scott:
I have two body molds and four head molds. I use two part foam exclusively. Drilling the high spots of a mold with 1/32 or 1/16 bit will do nothing to the mold or decoy but it will let the traped air out. For the heads I have drilled the bill, eye, and highspot cheek in the topside of the molds. Bodies got holes in the front, middle, and 3 near the tails.
Try a head and body without holes, figure out where your mold didn't fill out, and you will see where you need them. By the way you will need to drill out the foam from the holes after every pour.
My diver rig has 5 doz of my decoys so far, and now I'm working on widgeon and old squaw.
(The part of the mold you want on the bottom has the most volume, drill the ones on the top) my body molds are laid on their backs the drilled part is the bottom of the mold / decoy.
Posted by David Anderson
Time Posted: March 8, 2006 at 1:41 p.m.
I have been using 2-part urethane, 4lb, and been very pleased with the ease and simplicity associated with the 2-part. Can do three in an hour at the kitchen table. No mess.....just need 70-80*, some release and a couple measuring cups.
For heads I tried PorOKast and am thoroughly satisfied.....great detail, excellent paint holding, similar to 16lb in strength and I was using micro filler!!!!! The bills will not break off!
