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Blue foam for fiberglass mold ? what is it


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Is it something ya can get at a fabric shop ? Ive looked around but no luck so far .

 

Someone told me to use blue foam to make a shape for a mold i want to do for a hood scoop add on . Ive got a aluminum frame made thought of wraping it in sheet metal so it wont have any low spots in it . Is it possiable to lay fiberglass over sheet metal ?

 

Jason

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Jason:

You can lay fiberglass over anything. You can make a 'plug' out of any material you can get to hold the shape you desire. A plug is fiberglass speak for the object you make a mold from. I've hear of folks here using floral foam (found in a craft store) covered in duct tape. I've personally used beer cans, pvc pipe, sheet metal, masking tape all smoothed over with bondo, you name it. It helps if what you create can be painted, then later waxed, so the mold will release from it. I've heard of people using PAM cooking spray as a release agent. The fiberglass store (look around boat marina) even has some green slimmy stuff called release agent you can spray or roll on, it cuts with water so it's easy to clean up.

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Here is an example of Jack Atkinson's Z32 undergoing the widebody transformation. In this case aluminum AC tape was put on the body panels. Foam was then glued in place, and carved to the desired shape. Once you get close to the desired shape,Aluminum tape is put on top of the foam, and skim coated with body filler.

Sand, block, fill, and prime this skim coat until you have exactly what you want your finished product to look like. Spend the time here, it will make a much nicer finished product.

 

Once you have exactly what you want, mold release the surface and make your molds.

 

Hope it helps.

 

 

z32patternmy7.jpg

 

z32pattern2or7.jpg

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Thats not a bad idea with the styro foam stuff ive used aluminum tape alot in the past gives me a good idea for a wide body kit once i try to add height to my existing hood scoop that is . first things first get the hood tall enough to clear the engine .

 

If anyone wants to know i have a all fiber glass hood with a 4 inch cowl well its about 3 1/2 inches to short need like a 7 inch cowl as with a super charger there just is about 2 inches between the carb flange and the hood not enough for a proper air filter .

 

Jason

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Blue and Pink foam are USUALLY "Polyurethane", and will not dissolve when POLYESTER RESIN is applied over them. For the white "STYROFOAM" stuff, it will be dissolved when hit with POLYESTER RESIN, so you either have to paint it with latex house paint (or other sealant barrier) or use EPOXY RESIN in the layup so it won't dissolve.

 

The key is POLYURETHANE is universally compatible with most resins used today for FRP layup. This is the same stuff you get in most "SPRAY FOAM" cans at Home depot as well. If you are free-forming something using that foam and then cutting it down works well, and the foam is impervious to the Polyester Resin in the cheaper FRP Kits. I originally constructed my entire lower G-Nose Air Dam out of that spray foam, as there was no other Polyurethane Foam source locally...

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Just an other idea out of nowhere but, maybe that by blue foam, they meant that stuff that you use to lay your sleeping bag on when camping.

 

Sounds a bit bizzar at first but, I had friends that used to play something like "Dungeons & Dragons" but in real time, anyways, they used to take 1" to 2" PVC pipes as skeletons, that they would sandwish between two layers of epoxyed blue matress. once the epoxy dried thay would carve all sorts of "fantacy" shaped blades that they would then cover with silver Duct Tape to simulate swords and axes.

 

The big point being that this stuff is pretty tuff, it could withstand alot of hits plus moisture and dirt since they would spend entire weekends bashing at eachother and sleeping in the woods.

 

It's pretty stiff too but thin and flexible enough to bend and shape like you whant + it has the added benefit of making MUTCH LESS of a MESS once you're done carving and scrapeing.

 

Just my $0.02

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  • 11 months later...

Hey guys, old thread but I need more info on this foam. What size blocks do they sell it in at Home Depot and where in Home Depot do you find it(what department?).

 

Also is this foam like that green flower pot foam, I want to be able to shape it and then cover it with fiberglass and then remove the foam.

 

Thanks!

 

Guy

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It's in the insulation department in 4' x 8' sheets. It comes in 1/2" thick and 3/4" thick. You can also get it in thicker sections but you usually have to order a whole pallet. My local construction materials supplier stocked it in 1" thick pieces which was nice.

When you use the foam there is a thin plastic sheet that you need to remove first. It just peals off. Also if you use a hot wire to do any cutting make sure your protected from the fumes. Polyurethane foams emit some really nasty gases when burnt. 3m supper 77 spray adhesive works really well for laminating.

The blue and pink foams are superior to EPS white foam every way for this type of application. It sands and carves really well.

 

Derek

 

 

Hey guys, old thread but I need more info on this foam. What size blocks do they sell it in at Home Depot and where in Home Depot do you find it(what department?).

 

Also is this foam like that green flower pot foam, I want to be able to shape it and then cover it with fiberglass and then remove the foam.

 

Thanks!

 

Guy

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Just to throw it out there... Fiberglast.com sells 2 part poly foam mix you can pour in th a shape then sand out into shape... I have used it making speaker boxes.. and to fill boat hulls. I looked for large pieces of foam at craft stores and such with no luck... This you can mix and pour into a box as big as you need the piece and go from there... It can be covered with fiberglass resin w no effects like some foams...

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There was actually a show on Spike TV (Musclecar) where they created their own fender flares for a mustang they were going to track. They used the Blue foam from wherever (floral store or home depot), and stated that you can use anything to create the shape you want; i.e. any type of foam, sheet metal, cardboard, WHATEVER gets you the shape you are looking for.

 

The only thing you need to worry about is a release agent. They actually used aluminum foil as their "release agent." They got the flare to a shape they liked, wrapped the foam in aluminum foil, then started laying fiberglass over it. They had stated they did 3 layers of fiberglass for strength.

 

(Oh, and on a side note, they were testing different glues out to try and find something that would allow the blue foam to stick to itself so they could get some depth to the flares. They tried, I believe, 5 or 6 different glues out and finally found one that would actually hold the foam. They didn't 'tell' the viewers what glue they ended up with, but I'm 99% sure they found that the "Gorrilla Glue" ended up working the best. You can get this stuff at Kragen Autoparts or wherever.)

 

I have never fiberglassed before but it honestly didn't look too hard. Set the foam up on your fender then start sanding away to shape it into something you are looking for. Once they had their mold glassed, thats when they started to sand, fill with kitty hair fiberglass, sand more, then bondo, sand, bondo more, sand more, etc. I'm sure it is a very tedious process of sanding and filling, but the end result will be worth it if you just take your time.

 

Also, one last side note (I swear), the guys creating the flares also molded in bolts to their flare so all you need to do is drill a hole in the fender, and throw a washer and nut on the other end. Looks clean and took no time to do.

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A big question you want to ask is do you want the foam in there after the glasswork is done? If you don't, then using standard styrofoam is preferable, you can get it close, cover it with several layers of latex house paint, then lay your glass over it. Then pour in a solvent and dissolve out the foam afterwards.

 

There are places where having the foam in there may be advantageous, like a nose extension or lower spoiler. And if your flares are as big as mine, flotation in a water incident may come into play! LOL

 

But yeah, moulding in bolts is not that difficult, tacking them to a thin strip of sheetmetal and glassing over them is relatively easy, as is stuffing them through a balsawood stringer (which will add stiffness as well).

 

The Original G-Noses have mounting hardware in the nacelles (as did the early 240Z's) so blots in the glass is not a hard thing to do.

 

Just make sure you stiffen/strengthen the area you will be using as a 'clamping area' and beware when you bnmp against things as you will usually have a strongly adhered section, and the rest off somewhere else...

 

I ran my RR Flare onto a curb one day, and realized a pegleg car sucked...

I had em made strong (and heavy!)

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Just to throw it out there... Fiberglast.com sells 2 part poly foam mix you can pour in th a shape then sand out into shape... I have used it making speaker boxes..

 

I looked on that site but couldn't find it. Do you have a name for the product? I searched google but came up with a tone of different stuff, I'm not sure exactly what I'm looking for so that doesn't help either.

 

I am going to use it to make a speaker box.

 

Guy

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