Alright so hear me out Swaylock… SO I’m current in the process of building an insulation sheet surfboard. I just added the gloss coat and was ready to sand and finish her up until I noticed something… The board seemed way SOFTER than a typical board. I put pressure on the board in various places and noticed that I could put a pressure dent in it relatively easily. Now it’s not like the thing is a sponge but it definitely should not be this soft. Upon research and investigation, I realized something that I should’ve taken into account when I was fiberglassing the board, the foam I used is less dense than your typical eps surfboard blank foam. I am beyond frustrated with myself… So now I guess I have to sand back down to the fiberglass and add another coat which will add some time to the building process. So I ask you guys are there any shortcuts/recommendations that you would give me? What kind of sander should I use (Currently using a palm sander and an orbital sander)? How much more fiber glass should I add to the board (I already have two 6oz on the top and one 6oz on the bottom)? Is there any way that I can sand down a little bit but not until the glass and then add some fiberglass, or should I spend the time and sand until the glass?
I have already invested hours upon hours into this project, and I want to make sure the board will turn out sound so IF YOU COULD OFFER ME ANY ADVICE AND HELP ME OUT that would be greatly appreciated. Thank you.
I moved this to General Discussion because I think you will get more responses here…
As for the board…
Where are you located?
Did you read up on using insulation foam before building this board?
Including all the abortions folks have built over the years?
I am just wondering why you decided to use sheet foam?
Most folks know going into it that it’s kinda a throwaway experiment / fun project.
That said, how long ago did you glass? Have you postcured your epoxy at all? If you haven’t, postcuring will help harden the epoxy a great deal. I stick my boards in a warm car in the sun for a day or 2 after glassing. Watch the temps and keep an eye on the board. You don’t want it getting much over 100*F in there.
Otherwise, if you decide to sand down and add glass… Use a course grit and make sure there are no shiny spots on your board. You don’t necessarily need to go down to the glass in every area. Just think of it like a huge ding repair. This is gonna add significant weight to your board. Are you in a location where you cannot buy a blank?
Yeahhh, that’s kinda the thing you run into. Not to sound heartless, cause I’ve been there, too, and totally understand, but it’s part of the learning curve.
You don’t have to sand down to the glass. The layer of filler and gloss coat are just extra weight. On the plus side, the extra thickness they’d add to the skin if you glass over as it is and re-hotcoat/gloss might gain you some durability. It’s gonna be heavy. You’re not going to win any awards. But you should be able to surf your creation and apply the lessons learned to the next one.
Just as big a concern is making sure it’s vented. That foam loves to blow up when it gets warm.
I have never been able to figure out why people make surfboards with insulation foam. The stuff is horrible to shape. You need to use epoxy resin which is at least twice the price of polyestre resin; often you need to use twice as much resin and glass since the density is so low. The foam outgasses. If you ding your board and don’t notice for a while the board will basically fill up with water. Maybe just fork out a bit more money and buy a proper Polyurethane blank. I’m happy to be educated if I’m missing something here, but at the moment I just can’t see the point!
Chris is a nice guy…but really… cheap foam is just cheap foam.
Nice to know that I’m not the only joker around here. Funny answers from the crew. I was thinking power saw to make the board fit into the tash bin…Flirty fat girl in heels and mini skirt look good tonight…not so good in the morning.
Remember those of us who do not live in a traditional surfing area! Getting a proper blank for me would cost me at least $130 dollars and there are others i’m sure which have it even worse. Low cost hobby boards sudenly get a lot less low cost.
$130. That’s what blanks cost (including freight) here as well. Let’s say you’re getting your insulation foam for $40, so that’s a saving of $90 on the blank. Dealing with small amounts now, if you use 2kg of epoxy resin then that’s about $60. 2kg of Polyestre resin is about $30 so that’s a saving of $30. You’ve now saved yourself $60.00. That’s actually being conservative since generally the low density of insulation foam requires more resin and glass, so overall you’re saving is probably more like $30.00. I just don’t think $30 is worth it when you consider all the extra hassle and the chance of messing up badly involved with dealing with insulation foam.
I’m not in any way trying to tell people what materials to use for their surfboards. I’m just laying out my reasoning for using the materials I use. I’m just curious as to why some people do it a different way. There might be something important I’m missing!
OK for next one he will use better matérial, or other tech. For this one, sand your finish with orbital and coarse grit to have grip then lam an other layer off glass on top that warp rails with cut lap on bottom then finish. It’ll add noticeably stiffness.