polyisocyanurate

[coal_burner]

the foamie bug has bitten me again & a new and different build is about to begin.

my brother has a full sized dodge pickup truck & i am going to build a campable, popup, foamie, fastback cap for it.

their is one issue. it's going to be painted black to match the truck, and he has been known to camp in the desert southwest.

my old testing showed that extruded polystyrene begins to shrivel and delaminate under these conditions.

my solution is to use the yellow polyisocyanurate instead.

test samples with glass and 5 minute epoxy show similar strenth to the pink or blue stuff & it doesnt start to collapse until about 400 degrees (i tested it in the oven next to some pink stuff).



my 2 questions are: has anyone ever built with this? and: is it compatible with vinylester resin?

the vinylester should save me quite a bit of money if it's compatable.


i eagerly await educated opinions from those who have built more than i.

[aggie79]

I'm interested to know your results. I'm being drawn toward a foamie for my next build.

I'm also interested in the adult beverage count during the testing.

[wagondude]

This is only one post, but it sounds like it's a no-go. http://forums.iboats.com/boat-restorati ... 07267.html
I'm sure there is more out there, this was just the first one I pulled up.

[Bogo]

This is only one post, but it sounds like it's a no-go. http://forums.iboats.com/boat-restorati ... 07267.html
I'm sure there is more out there, this was just the first one I pulled up.

They are talking polystyrene foams in that thread.

Polyisocyanurate foams are resistant to most resins used for fiberglassing. Just do a google search on polyisocyanurate vinylester resin compatibility. Knowing how to find information is vital for designing.

http://www.elliottfoam.com/faqs.html

Can ELFOAM be used with polyester vinyl ester and/or epoxy resin systems?

Yes. ELFOAM is compatible with most resins and their corresponding processes.

They will even see you sheets that are already kerfed...

[GPW]

You DON”T want to hot wire that yellow foam , although I’m not certain , it’s “reported” to give off Toxic gasses when heated ... However it cuts and carves Nice and you can use polyester resin on it ... We did find it more brittle than the usual styrene foams when used on planes (miniature RC aircraft) ... and Pricy ...

[coal_burner]

Good info, tnx.

I figured the foam would be one and a half times the cost (adding $30 to this small project)
But the adhesives would cost half as much (subtracting $100)
I should be able to get the project roadable with the leftover glass from the bolt I bought for BUB!

Hopefully the main part of this build thread will only be a month long.

[GPW]

That’s right huh !!! You built the BUB ... And that other rakish looking modern trailer ... How did that one work out for you ?

[coal_burner]

The woody was loaned to a friend (who funded its construction) to make a quick run out to california to pick up furniture.
She had not 1 but 2 blowouts, each at over 70mph. I am proud to say that the trailer didn't sway at all during either one (Thats saying alot when the tv Iis a small car towing a standie)

Unfortunately that "quick trip" has been over 8 months long so far, and does not appear even close to being over.


Picking up building materials with my own small car is a bit of an adventure without a trailer.

The new build will start today with the purchase of foam and wood.
Then the shaping of the forward bulkhead.

I'm wondering if I should do the cutting and shaping with the skins on, or off?

[GPW]

What kind of skin does it have ?? Aluminum , paper, plastic ??? You might want to test some small samples first ...

[coal_burner]

I plan on peeling all of the skins off before 'glassing, but because of how brittle this stuff is, im thinking the skins may help it survive the cutting/sanding/dry fitting stage with fewer crushed corners to have to fill in later.

[GPW]

That’s true huh !!! Garage Rash !!! Once it’s glassed it’ll be fine as you already know !!

[coal_burner]

The build has begun.

After a whole bunch of research on the curing requirements of vinylester, I've decided to just go with epoxy.

Since I don't have to worry about things dissolving, I can put some extruded polystyrene scrap to good use.

Here is the forward bulkhead, shaped to conform with the rear of the cab.
Im sure it's going to be fun figuring out the curves in the sides, and how they are going to match up with the curved top.

[atahoekid]

Looking forward to seeing the pics. I used epoxy too. Worked great

[coal_burner]

the next step has been taken.

2"wide strips of 1/2" OSB have been cut for the mounting rails.

the bulkhead foam has now been epoxied to the front rail



the 2 sides have also been cut & skins removed



things i learned today:

this foam smells HORRIBLE when the skin is peeled off

it is brittle enough that i put a crack in one piece while peeling the skin off

it is fairly soft & wobbly when there is no skin there to keep it rigid

[GPW]

I don’t think it self heals when damaged either...