I built a fish a few months ago out of Home Depot Foam. I glassed it with 3 layers of 6oz on the deck 2 layers of 6 on the base. I have noticed in the past few weeks the deck has felt very spongy. I am just wondering if Idid something wrong or if this is a common problem. One other thing I sealed the foam with Light Weight Spackling mixed with a little water. Any info would be great
my money is on water intrusion…
clean off your wax and closely inspect for cracks or other possible points of ingress.
Alright, But from the soundsof it I did nothing wrong? I was just wondering if it had something to do with the Epoxy not bonding with the spackling or something along those lines. Thank you for yourresponse
With spackle, water is your enemy.
Maybe just spackle is the enemy.
Actually at your level maybe EPS, without all the shaping tools of the trade, is your enemy.
You’ve got a lot of enemies.
Check for dings or cracks i would think afoaf is right "eps + water= pain"
Otis - Should I have Not used spackle? The reason I am using Home Depot EPS is b/c I live on the Great Lakes. There are no Blank factories within 400 miles of me. I cannot afford to ship 1-4 surf blanks for $120 So I am trying this method. I am planning on building another board in the next few weeks. I am curious about using the XPS pink stuff. I know that foam is subject to Delam when not properly vented. I would rather not use the pink stuff if I can help it. So if anyone has a solution to this problem please let me know. I went over the board this morning. I cannot see any visible cracks or holes or anything.
The Home Depot foam is only about 1lb/cuft. It is a bit too soft with out a hard skin.
Is the spongy feeling the whole top moving or does it seem like the top has delaminated?
I have had on bad delamination with HD foam and that board was spackled. I’ve since used epoxy and microballoons or other filler if I want to seal the blank.
You may have better luck with the XPS. The beauty of the XPS is that pinholes in the lam won’t be a problem.
It feels like the whole top is moving. Not just one area
lot's of stuff in the archives about making XPS work...
maybe shoot Surfding a PM.
The special order desk should be able to get you heavier densities. I ordered a custom density block from my local HD but it took some doing.
There are various types of EPS sold at Home Depot, and they’re not all created equal…
Being in Canada, the Home depot stores here stock EPS manufactured by : http://www.plastifab.com/
I comes in 2 densities the lowest being just under 1lb. and the high density stuff I use (Plastispan HD) which is 1.5lb…
I use the 1.5# which is great to shape, has a very tight/small bead structure that doesn’t flake off and leave holes… Because I use a table to bend the rocker into the foam after foiling the ends , I buy the 2" thick Plastispan HD… It costs $13.00 per 2’ x 8’ sheet…
Sounds like you left too much spackle on the eps .if you’re getting delam in a large area of the skin… If you’re using this method you need to sand off all the excess spackle,leaving it only in the larger voids… also if you leave the dust on the foam this could lead to a bad bond as well…
. A better/stronger choice would be to spackle with white micro balloons with a touch of white pigment and epoxy slurry…
Sounds like the whole top is delaminated. Did you let this board get too hot?
I left a board in the sun to “post cure” and forgot about it. When I remembered, it was like a balloon. It swelled up at least an inch bigger and the top was delaminated from the blank. I pulled it out of the sun, but it didn’t shrink back down all the way. I can push on the top and it will go in about a 1/4" or more. It has wood rails, so I don’t think the delamination has caused it to get weaker. I just keep riding the board. When it gets in the water it shrinks a bit from the difference in temp so the top tends to pull back down. In time water will get in and it will start to get ugly, but I don’t care.
I don’t know what XPS does when it gets hot, so I can’t say what will happen on the XPS blank. If you go with XPS, leave the surface rough, use a 60 or 80 grit sandpaper for the finish, don’t spackle.
Good surfboard EPS isn’t as vulnerable to water intrusion as the more airy and porous low grade EPS as is found at Home Depot.
Once you get water in to it, it deteriorates pretty badly, spackled or otherwise.
XPS is a great foam for surfboards and carries a reputation of questionable validity; I have a couple XPS boards that are tough as shit…no problems at all with delam.
Surfding has a lot of good posts on the matter…the key is to key! Key up the surface a bit to create an improved mechanical bond. I literally take a (CLEAN) wax comb and rake the foam with it before lamination. This is an extreme approach, yet works really well. Plus, if you’re going with the pink, you may paint/tint your board anyways unless you are eminently at peace with your masculinity, in which case I’d say you go girl!
; )
Try Ken at Segway composites…he may have cheaper shipping options, offers fantastic foam or, at the very least, may be able to direct you to a supplier closer to you.
Also, Brian at Greenlight Surf Supply is relatively close…he might be a good resource to check with.
totally agree with Afoaf, used to build boards out of cheap eps, got sick of the water issues, been building XPS laminated with 1 layer of 100% bamboo 3oz woven cloth for about 2 years now, and I have a board 18 months old which has been ridden 2-3 times a week (bit of a magic board… if they exist… ) no delam issues, no heel dents in the deck also!
1# eps is pretty much crap. Look in the phone book under insulation … or on the web. Find an EPS block foam manufacturer in your area … there will be one for sure. Get some nice 2# density foam from them and hot wire the profile (thickness). Your problems will be solved.
great thanks for the help guys. After reading more and more I think Iam going to give the xps method a try. My thoughts are to build a Simmons inspired 6'4" Twin fin. Im sure you will see more posts from me in the future. I have never actually seen one in person. Just on the computer. From the looks of it it would be great for our little Wind Blown Lake chop we surf. If anyone has any pointers in regardst to this type of board chime in. From the littleknowledge i have as of yet. it seems the nose of the board is convex then to flat slight single concave in the tail. Is this Correct? Also what about rails?