Diy sup foil

[808sup]

Thanks for the reply supuk. I’m about to set a block of high density foam into an old race board I’ve had lying around. Now that I’ve reached the point where I am ready to install the new foam I have another question.  My board has the cheap popcorn foam.  Would it be better to use gorilla glue to glue this block in? Or use your method with the fiberglass bed underneath? I don’t want to melt down😳

[surfcowboy]

808, I'd lay in some 4 oz glass just to be sure. It's simple and cheap insurance as it ties it all to the top skin.

[808sup]

Shoots! here is a picture of the foam I'm talking about.

[jrandy]

If not using foaming PU glue, I would be tempted to make a lightweight fill from resin and microspheres and 'frost' the sides and bottom of the cavity, sealing the foam and filling in where the beads are missing. Then I would let it cure before adding glass, resin, and the HD block.
Doing it all at once with alot of resin between insulating foams could trigger a meltdown as you mention. I redid a board a couple years ago and the first finboxes I set were cavitated by meltdowns on the bottom outside of the boxes. It was not visible from the outside. That foam was also lighter than normal EPS.

[supuk]

I would defiantly not use pu glue, I would use at least 1 layer of 6oz under mine to connect it to the bottom skin. Use a slow curing epoxy to bond it in, you may want to use a coat of epoxy/mb before just to smooth the bottom out a little first to avoid pooling resin

[Surfside]

Why not use PU glue? Curious?

[supuk]

Because you relying only on the shear and compressive strength of the foam were if you use epoxy and use a layer of cloth to attach it to the bottom you are using both of the above plus the shear strength of the glass.

[supuk]

Because you relying only on the shear and compressive strength of the foam were if you use epoxy and use a layer of cloth to attach it to the bottom you are using both of the above plus the shear strength of the glass.

Sorry I didn’t mean shear at the end there I’m meant tensional

[Surfside]

Thanks.

[surfcowboy]

If you check my thread you can see that the glass isn't just under the cassette, it's wrapping from the bottom of the board, connected, under the cassette and then out the other side to the bottom skin again. You're making a fiberglass box really instead of just glueing foam to foam with glass over it.

[808sup]

Thanks guys for your help. I skinned the foam with a thick mixture of resin and microspheres. Then wet out some 4oz. and set the high density foam in place as suggested. I have routed the mast tracks to fit and that leads to my next question. Should I use the same resin and microspheres to set boxes? Adding weight to hold in place till resin cures. Then glass over to taste? Or should I set them in glass as HD foam and then glass over?

[supuk]

Thanks guys for your help. I skinned the foam with a thick mixture of resin and microspheres. Then wet out some 4oz. and set the high density foam in place as suggested. I have routed the mast tracks to fit and that leads to my next question. Should I use the same resin and microspheres to set boxes? Adding weight to hold in place till resin cures. Then glass over to taste? Or should I set them in glass as HD foam and then glass over?

with the futures having a flange i don't use any glass under them if you are using a chinook or standard style box i would be tempted to put some under although probably overkill

[supuk]

Got the board laminated and inserts in over the weekend

[surfcowboy]

Is that deck sunken?

Also, how do you finish these? Is it rattle can or a sprayer? I'm going to paint my wings but I'm considering leaving the mast black since it can't off gas and balloon.

[supuk]

Yes this one has a deck recess, The wings I do the same as a board hotcoat and then a clear wings I sometimes do with a can if I don’t have a gun out.