Skimboard tips

I’ve searched and read the stickies, and they have helped a million but I have a couple more questions.

Since my local beach is on a river with a shallow beach area where we skim, I wanted something durable, but with foam to keep it lighter. This way, it wouldn’t be as prone to sink once over slightly deeper water, and wouldn’t get dinged up by the sticks that sometimes wash up. (I do my best to pick them out, but hey). I decided to use 1/4th ply (the lightest I could get) and some foam I got at lowes (It was dow, xtra-tuff or something like that, I had to peel a paper backing from both sides), with one layer of glass on the bottom and two on top. I’m not going for super light weight, more durability. I got some cloth from my shop teacher, I think it’s e cloth, just bidirectional even weave. I’m not sure on the weight, it’s pretty heavy, but I don’t mind if it’s a little heavy, it won’t be as heavy as a 1/2 inch ply wood board with one layer of glass, so that’s all I care about. I also got a small amount of carbon cloth to reinforce the top with for where you jump on it. I got some resin and hardener from a local plastics supply company. I’m going to start the layup tomorrow, and I had a few questions. When doing a hand layup (After this point I’ll be using vacuum bagging, but for now I wanted to keep the costs at a minimum, I have around $60 invested so far, I could have bought a cheap foamy for $60, but this is so much cooler.), do I soak the fiberglass in the resin, lay it out and then squeegee the excess off, put some resin on the foam, layout the cloth, put more resin on and then squeegee it out, or do I lay it out and just put the resin on top, and spread/squeegee it out. Also, do I have to sand between layers? What about painting? When is the best time to do that?

Thanks,

Nathan

Hi Nathan,

Is the foam you’re using EPS? if it is, check your resin and make sure it is epoxy. If your resin is poly, it’s going to melt your foam. you can hand lay up your foam with the two methods you suggested but some like to keep the EPS foam from sucking up resin to keep things light so they use spackle or a mix of cabosil and resin to coat the foam before the fiberglass/resin. HTH, post pics when done!

cheers,

Rio

Yes, it is epoxy resin. Any tips or links on how to lay it up/get the epoxy on the cloth?

Thanks,

Nathan

Glass it just like a surfboard. Seal it first though. search for glassing tips.

Make sure the epoxy is measured exactly or you will have a sticky piece of crap. Good luck!–kevin

Hi Nathan- Just drape the cloth first, and then saturate it with your resin. The cloth will soak up the resin, and you use a squeegie to move the resin around. Once you try it, you will get the idea, and the rest will be easy… especially with epoxy. because you have never tried it before, I recommend perhaps trying a little test piece out of scraps. Have fun! -Carl

As was said, with epoxy you’re going to want to seal the foam first. Use micro ballons or fumed silica to thicken up the epoxy to a honey-like cosnistency in order to fill up the voids and provide a better bonding surface for your glass layer. Let it set before doing the glass lay up.

Is there anything else I can use to seal it? I don’t have any microballoons. I’ve heard from the RC world that baking soda makes a good filler?

Well, I oopsed. When I glued it up, I forgot to check which way the natural rocker of the board was running, and I glued the foam on so that the bottom of the board would be concave. Whoops! I may have to start over, at least I caught it before too long. I’m trying to save it, I wet down the ply, and then stacked alot of weight on it with the nose propped up, I’ll leave it that way for a while. How long should it take? Also, if I do have to start over, what kind of foam should I use? Is the EPS you guys are using for boards just like styrofoam? With the little beads? Or is it like what I have, smooth texture throughout. It seems this would sand better, but ply and foam are cheap, fiberglass is not. I don’t want to get it built and find that it’s not the right foam.

Thanks,

Nathan

Oh yeah, the foam doesn’t say anything buy xtra-tuff in english, but in spanish it says “Polysacaurinate” or something like that. I speak a little spanish, but not technospeak. Is this EPS? how do you tell the difference between Eps and Xps?

Thanks,

Nathan

Okay, well I think this board is botched. I found out that the foam is Polyisocyanurate, which I haven’t even heard of before. Can I use this? Or is it a lost cause? It’s closed cell. It’s called Tuff-R insulation, I got it at lowes, yellowish color. I noticed that the bare foam got much darker after being left in the sun.

Well, I’m going to go get some EPS and do this like a surfboard, with a shaped stringer down the middle, it will be easier that way. The way it is now, I have to rocker a full sheet of ply, and it’s hard to do without a vacuum bag system, I just checked it, and it’s rockered the right way now, just all warped etc.

Okay. Let’s do it right this time. the problem I had last time, which cost my $20, was this. I just thought of an idea, and started executing it. I didn’t think. Hmm. How could this go wrong, I just thought of the easy way and did it. I bought the foam that seemed easier to shape, used an Idea that seemed easier etc, until I got a warped peice of foam and wood. Also, the PU glue didn’t bond to that foam very well, I could chunk it off quite easily. Now, I went and got some EPS, the stuff I wanted in the first place lol, and an piece of 1/2 oak hardwood for the stringer. I was thinking 1 1/2 inches of rocker myself, not too much but not too flat. Does anyone have any ideas on the profile? How far back to carry the rocker etc, also, what about the shape of the board, I was thinking of doing a squared tail as I want manueverability, but it seems that most manufacturers just round the tails. I was thinking maybe the water slips past easier with more organic shapes? Also, do you have any pointers on the shape of the board? Length, width, how things taper together?

Thanks,

Nathan

Oh, what’s the best thing to use to glue two pieces of EPS together? I need to make it thicker at the nose to sand in my profile (I’ve had enough of trying to bend the profile in without a rocker table or vacuum bagging setup).,

Hi Nathan,

From what I know about foamie skimboards, the foam they use is divinycell. It’s a denser foam than what you can typically find at the hardware store. The reason for denser foam is that unlike a surfboard that planes on water, a skimboard needs to withstand the forces of sand and rider. regular EPS found at your local hardware shop would most likely crush (and what about gassing?). You can prevent the crushing by using more fiberglass (how much, I don’t know). So if you want to make a skimboard with least amount of $$ and headache, try using just ply first and glass it. Skip the foam until you can find a supplier for denser foam. This is just my opinion and I am by no means an authority on anything, just basing it on what I’ve read before. If you want to continue on your foamie project I’d still be glad to help.

Cheers,

Rio

See, that’s the problem, I can’t seem to get a decent rocker profile going with the ply, it’s all too twisty, none of it is flat enough to start from. Hmmm.

Okay what if I skinned the bottom with some other foam before fiberglassing it? I have a sheet of 3mm foam from here http://www.depron-usa.com, I could put that on the bottom of the board. I’m just having too hard a time with the ply, as I don’t have a rocker table etc. My fiberglass cloth is pretty heavy too, I think it is more than 6oz. I bought it from my shop teacher, he said that it would only take about 2 layers of it to get a nice strong hard surface.

Okay. This is what I’m going to do. I’ll use the 1/2 inch oak to create my Rocker, and then glue the 1/4 ply to that. After that is done, I’ll put the foam in on top of the ply, and sand it to shape, glass and be happy. Sound good? I think this should give it enough durability.

Edit:Should I use the old foam I had? It is a little denser than the EPS, I did a search for it and found that it is very similar to the PU used in surfboards, but formulated so that it would be less toxic.

Hi Nathan,

'found something that might help you.

Skimboard Construction

Seems like they have a program for making outlines and rockers…cool!

Cheers,

Rio

They are using EPS, so as long as you use a stringer it must be fine. I’ll take the extra piece of ply I just bought back, enough messing around with trying to come up with a good way to make it, I’ll just follow thier directions. I had already looked there, but for some reason I couldn’t find it again. Thanks for the link! Gracias por su excellente ayuda. hehe.

Nathan

Well, I’m started on the stringer, it’s coming together nicely. I’m basing the deminsions off of the Vic Foamy and the rocker from a pic I saw on another site lol. its got about 1 in of nose rocker and less than 1/2 in of tail to give it a little loosness.