Landracing Forum
Bonneville Salt Flats Discussion => Build Diaries => Topic started by: Brian Westerdahl on November 14, 2009, 09:36:42 AM
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I know this has been dicussed before but I can't find it. We are going to build a canopy for our lakester to enclose it. We were wondering what kind of foam you use to make the shape that you want. Is there one special density that works best. We don't know much about this process. Any advice would be appreciated. Brian #7796
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An advertising display company might have choices of foam that can be shaped and contoured with a smooth finish. Maybe in Wenatchee or over on the coast.
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It's scary. The spam bots are almost starting to make sense.
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A while back I helped a friend make his canopy and we used blue foam to make the plug and it was easier to sculpt than other types of foam. Then we made a mold off of the plug and lined the mold with one piece of felt. Also keep in mind of the angles for distortion of your sight from inside the car. I am sure there are other methods and others will chime in. Tony
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Brian, I used EPS foam to build the buck for my 21 foot long streamliner body. You can also use urethane foam but it cost about three times as much as EPS. ESP is basically the same foam used in making Styrofoam coolers. If you decide to use EPS foam, you need to use Epoxy resin and not polyester. The polyester resin will melt the foam. It can be cut with a home made hot wire cutter and sanded to the final shape you need. I covered my foam with drywall compond and sanded to get the final smooth surface. I used a 2lb density. If you look in the build diaries under New I/GS build you can see some photos of my body. If you IM me I will give you a step by step description and material list of what I used. I am not a expert in this field but I think my streamliner body turned out OK for my first try at laying fiberglass.
JerryO
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Peter Jack made a comment about the spambots a few posts ago. I just looked at this thread and dicovered said spam -- and deleted it. Now you know what he's talking about.
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Thanks guys. I will do some checking and get back to you. I will have to check and see where I can get some around here.
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Looks like the same spam bot again Jon. Persistant little devil!
Pete
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It can be cut with a home made hot wire cutter and sanded to the final shape you need. I covered my foam with drywall compond and sanded to get the final smooth surface.
In my experience, a band saw works just as well as a hot wire cutter if not better. It usually takes a fairly big band saw, but saves building or buying a hot wire cutter.
Drywall compound works well, but if applied too thick takes forever to dry and tends to crack. It can be applied in several thin layers without issue.
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I spent a half-hour riding the snow thrower and then some time firing the wood boiler -- and there's my excuse for being tardy when it came to excising the spambots little leavings. But they're gone once again.
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Brian, If your parts are not too large a band saw does work great. Since I was using 3'x4'x8' blocks of foam to make my body, it would take a very large band saw. I made a hot wire cutter that could cut through 4' thick foam for about 12 bucks. I used my welder for the power source. Only need 5 amps with a .030 wire. If you do use a hot wire cutter, be sure you use EPS foam and not urethane. Urethane foam puts out a toxic gas when melted. I also used the drywall compond because if you use automotive body compond, it can melt the EPS foam because of the heat it can generate. Urethane foam seams to handle the heat much better, but again it cost a lot more than the EPS. You do have to apply the drywall compond in layers. As stated before, if you put it on too thick it will take forever to dry and will crack. Again, I am not a expert in this, just passing on info on what I did and cost was a factor for me. This was not the best way to build the buck but was the most cost effective way for me. I will send you more detailed info on this some time this week end.
JerryO
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Ok thank you very much. Brian
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Aircraft Spruce has non reactive foams.
A method I used was to laminate multiple blocks of Home Depot pink house foam insulation, shape it, bondo any imperfections out and then used 3m Super 77 spray glue and aluminum foil to make a protective barrier (plus you could really see any imperfections) and made a great substrate for releasing agent.
The poopy pink foam is cheap and available anywhere and while its true that it is very reactive with resin...the "cover with foil" method worked really well and was really inexpensive.