Wasted foam ?

[rustytoolss]

Planning to buy my sheets of XPS foam soon . I think I will need 10 pieces (ttt). Since I've never built anything with foam board before. How may sheets of foam , did you waste (ruin) building your foamie ?

[KCStudly]

None. If you screw something up it is easy to glue it back together.

Okay, in truth I do have a small pile of off cut chunks and strips, plus several 2x8x3/4 slabs that I apparently over bought, but the yield is usually very good and you will find all kinds of useful things to do with the excess chunks (tongue box, clamp savers, knee mat/pad, drink cozy, etc.)

Google "free sheet goods optimizer" to find an app that will help you enter your cut sizes and determine the least number of sheets you will need.

[yrock87]

Once again I find myself agreeing with KCStudly and wondering what else I can contribute to the conversation. I picked up 12? 2x8 sheets of 1 inch foam and have 2 left over. then again I still have my hatch to potentially insulate.

having said that I had minimal waste. I probably lost about 4-8 sqft total (a quarter to half a sheet) that were not used on the build due to cutting all the curves. but a lot of the cut offs were able to be cut to fit smaller areas. I also tried to some degree to maximize use rather than allow waste (by building my floor 24 inches in-between wood framing (14-24-14) to accommodate at least one full size sheet opposed to equidistant frame members which would result in (18-18-18) wide bays and more waste (and more work).

also, I have found uses around the house for extra. one of my spares got cut down to fit above my window AC in the living room for the summer.

[GPW]

OK, I know it’s a bit nerdy and geeky , but we build RC model planes out of our foam scraps , or if big enough save em’ for the next trailer build ... Foamies are like potato Chips , you can’t have just one...

[rustytoolss]

I really did not think that there should be much wasted foam. Unless a guy just had some really bad breakage. I think that my biggest area of concern will be making the curved front surface. By the time you cut out for the door ,windows, cargo doors, etc. I should have a small pile of leftovers.

[lthomas987]

I have some bits and pieces, but I broke none, and I only went back for foam once, when I decided I was doing all my internal framing in foam as well as the exterior and I only wanted 1" for that. I came in exactly as planned. I did once I cut the rough outs of the major shapes do some experimentation with offcuts before working on the real stuff. When I was cutting channels with a solder gun, it took a few passes to get it right but I did that on the pieces that had been the corners of the sides. I then used those same badly cut channels to figure out gluing that stuff up. I have a pretty small pile of foam in my garage left. Considering a custom fit cooler... or who knows.

[rustytoolss]

None. If you screw something up it is easy to glue it back together.

Okay, in truth I do have a small pile of off cut chunks and strips, plus several 2x8x3/4 slabs that I apparently over bought, but the yield is usually very good and you will find all kinds of useful things to do with the excess chunks (tongue box, clamp savers, knee mat/pad, drink cozy, etc.)

Google "free sheet goods optimizer" to find an app that will help you enter your cut sizes and determine the least number of sheets you will need.

I'm not a computer wiz like some are. Have looked at some sheet goods optimizers online. Question time. Can I draw out my project's profile, and size needs (my camper is going to have a radiused front frontal profile (like some teatdrops). Then enter 48"x96" sheet sizes ? Can the optimizer figure out the best cuts with a radiused cut ?? Everything I see is for square or 90* cuts.

[KCStudly]

The free one I used would only do straight cuts, but it would be easy to figure out which pieces would fit into your radius off cuts, and then just leave those out (since you know you can get them out of the drops).

I guess on a simple build this could all be done on paper (paper doll cut out method to scale even), but for my build where I used the 5mm marine ply pretty much everywhere, and the cost was not insignificant... and I did have the luxury of a full blown 3D CAD model (i.e. a well detailed and accurate cut list)... and I traded labor for saw time at a cabinet builders shop who I could give the cutting schedule to, it just made a lot of sense to use an optimizer. Another nice feature, for the wood anyway, was that you can specify grain direction on the parts where that matters. Just saying.

Don't get too caught up in it if it isn't needed, but it can be a very useful tool for bigger projects where it is worth the time to save a few sheets. By breaking my bulkhead and floor skins down into smaller butt joined sections I was able to go from 16 sheets to 13, saving about $165. Still, due to the several large panels and many longer strips, my plywood "waste" was still about 35/ct (but I haven't finished building lantern boxes yet ). On the other hand, after doing all of the work to get the butt seams nice and all, I was regretting not just having bought more full sheets. Getting down to the wire and thinking if I screwed up one large panel I would end up short and have to eat additional shipping costs ($100) also had me second guessing, wishing that I had hedged my bet and just bought the extra sheets anyway (it all worked out in the end, tho).

With foam it isn't so complicated. No grain, cut and paste, and if you run out all you have to do is pop round to the big box again (at least in my region where the foam is readily available).

[lthomas987]

I didn't use a sheet optimizer. I drew the 4x8 sheets on some graph paper and optomized by hand. Worked out ok for me. Biggest pieces first, then fit the bits in around. I actually ended up using some of my off cuts as forms for my hatch and stuff too. I'll see if I can find my notebook and post a picture but I think it succumbed to a paint spill.

[rustytoolss]

Optimizer got me down to 8 (4x8) sheets of foam !!!!!! . In my head I was thinking I might need up to 10 sheets. And I will have plenty of left over pieces from the scrap. Plus I will have even more leftovers when I cut out door and windows. There's a chance I could get by with 7 sheets of foam

[rustytoolss]

Well I'm getting my materials together. Just got back from HD, got them to do a price match of $28.99 for 25PSI Pink Board, and a 10% off deal. So my Pink foam cost me $26.09 a sheet . Saved $7.27 per sheet, and did not have to drive out of town to get a good piece.
Got my plywood, canvas, TBII, GG, Frame is almost done (still need to stretch it 30") stripped a RV for windows, door, power system. I took everything except for the air in the tires .
So once I get my frame stretched, I'll be able to start Heck I've even got a plan or not!
Like Oliver Hardy used to say to Stan Loral...."This is another fine mess you've gotten us into"

[GPW]

Good Price !!!

[rowerwet]

If you have a sheet and a half of 4x8' foam left, you have enough to make a sawfish kayak

[Mary C]

I used my extra foam pieces for all sorts of things. I glued three pieces together dug out the middle and now have a thing to cover my outside water spigot. i used one piece in the back of my truck to save my knees. I used and continue to use a piece for laying under the trailer, auto, truck, and the tractor. the small pieces in a pillow case to use as a target in front of a hay bale for the kids I drew a bear on it.

Mary C.