repairing an old mistral naish titan

rgomez · Joined: 13 Dec 2012 Posts: 112

A friend and I are repairing an old board that I picked up for free. The main damage was a gash on the footstraps area which after water seepage turned into a soft spot with seepage going to the underside of the board.

Opening up the board revealed a different kind of foam compared to eps. I'm not sure what to make of it, it looks like there are bits of thermacol with pu foam. It's clear the bottom was repaired before.

Can anyone shed some light on this?

Thanks

dllee · Joined: 03 Jul 2009 Posts: 5329 Location: East Bay

Brown stuff looks like rotten divenicell or a high density non water absorbing styro foam. Rotten by too much water with heat, pressure, and cooling.
It's OK, should be filled with microballoon mix, then glass the heck out of it with 7 layer's of 8 oz at the foot area, 3+ at the bottom, and around 5 in the deck where your feet aren't located.

U2U2U2 · Posted: Sat Jul 01, 2017 2:21 pm Post subject:

I don't see the significance of what it is OR what it used to be.

Remove it, fill with 8lb pour foam, carbon glass glass.

dllee · Joined: 03 Jul 2009 Posts: 5329 Location: East Bay

It's highly probably the brown divinicell, or airex, or poly blow foam, adhere's quite well to the white styrofoam, so trying to remove the brown would be a bit.h, tearing out chunks of white that is around 3/4 lbs density.
Of course, you can buy 3/4 lbs styro at home Depot for very little, but trying to stuff it in there might be problematic.

U2U2U2 · Posted: Sat Jul 01, 2017 5:56 pm Post subject:

The white stuff is EPS. The weight is unimportant for this discussion. It's probably 1.

Dig out , with a router , bread knife , whatever. The EPS that comes out with, so the cornflakes what, replace all with pour foam then epoxy over, using carbon and glass. Necessary to extend repair to good sound area.
It's a little time consuming , and costly..materials epoxy , carbon glass pour foam .

thombiz · Joined: 25 Jun 2007 Posts: 799 Location: Corpus Christi

Looks like 2-part expanding urethane foam. This used to be a common solution for large soft spots. For a soft spot one would dig out the crushed EPS and replace it with 2-part urethane. Problem with the urethane was it was difficult to get exact reproducible results from batch to batch. Notice the variance in bubble size. Another problem was it was exothermic. If you poured too large of pieces, the heat from the chemical reaction would heat the thermoformed skin and cause it to warp. The thermoformed skins were a real pain to try to repair.

jingebritsen · Joined: 21 Aug 2002 Posts: 3371

since you may have destroyed the outer shell, you may as well build back correctly.

see www.boardlady.com for best choices

eva knows her stuff