I posted on here awhile back about how to fix a damaged glue seam from a hotwired xps blank. The reason I used xps is because I wanted to expirement with infusion. There were a lot of firsts for me on this build. I’ve been building boards for 8 years, but have never messed with infusion, I had never even messed with vacuum bagging. I did a lot of research, but there was very little information on infusing a surfboard. Most people told me not to do it, that I would crush or twist the blank, or it just wouldn’t work. I decided to just go for it. Made a few mistakes, that I will correct next time around (mostly causing a little sanding and some wasted epoxy).
To prevent the rocker from flattening or the blank from twisting, I did a hand layup of carbon tape around the rails. This was my first time ever working with carbon. Like I said, lots of firsts on this one. I doubled up my tape line in an attempt to get a clear visual of where to cut the lap. It didn’t work very well and I ended up basically peeling and cutting. I went through 4 razor blades on a 5’5"… not sure how I can improve this step next time around. All in all, it did its job. The carbon perimeter made the xps blank pretty stiff.
Next was time for the infusion. I used spray adhesive to do a dry layup of the whole board. I used 4 oz E cloth, 2mm lantor soric lrc, and sandwiched with another layer of 4 oz E cloth. Peel ply on top of the glass, infusion flow mesh over the rails where the soric was not covering, spiral tubing running the length of the board on the bottom and deck, one for my infusion line and one for my vacuum line. Finally a bag over all of it. I pulled vacuum on all of it, made sure I had a perfect seal, and opened the resin line. It started off working really well, but because I had spiral tubing running the length of the board on my vacuum line, epoxy reached my vacuum line well before the whole board was infused. This caused me to waste a fair amount of epoxy. Something I’ll correct next time around. My other problem was the peel ply got bunched up in a few areas causing some ripples and high spots that will need to be sanded.
overall, for my first time, it went well. I am going to sand it down a little bit, pin line where the carbon meets the soric, and do a very thin fill coat. The board is a little heavier than I expected, I plan on maybe sandwiching the soric with 2 oz bottom and 4 oz top next time to save some weight.
About 6.5 lbs. it is extremely solid. I pressed into it with my thumb as hard as I could and no pressure dents at all. Time will tell if the vacuum infusion and Soric core will help with xps delam issues.
i was pretty nervous when I opened up the epoxy line. Learned a lot. I’ve got some good ideas to get it to infuse better next go. Only thing I’m worrying about on this board is it being to stiff. The carbon rails did a perfect job of maintaining rocker, but man… the carbon rails mixed with the Soric… this thing is stiff.
stiff skins, stiff rails, stiff core… will make a stiff board. From my research i found that stiff “hard” skins gives a stiff feel even if overall board is “flexible”, glue a soft thick eva pad under feet and board will feel softer.
Thank you for posting this. I have been thinking about how certain builders up here in the Northwest have been doing their boards. There may be a few different techniques, but the overall process is the same as yours.
It’s been a while since we’ve talked story about Coil’s builds, but one thing I remember coming out of the Coil and the compsand and the R.Stewart threads was that flex is at least parially a function of thickness relative to length. Part of Coil’s formula was to adapt their shape to their build-process, by which I mean the way they foiled their shapes more in order to get more flex going.
We had a LOT of discussion about how a 1980s foil with a high-strength build will turn out to be rigid. Bert Berger was talking about doing HPSB shapes with his process that were 24" wide and less than 2" up the middle. Etc.
If you’re building stronger then you don’t need to retain the same overall thickness that it takes to keep a conventional PU/PE build intact.
The Soric I got was 50" LRC 2mm. The LRC I believe has bigger hex cells and uses less resin. I’ve heard there is a 1.5mm out there but could not find it in LRC. Kinda pricey stuff, especially when buying small amounts for testing out the material. Those boards built in the PNW are lighter than mine. I’m not sure if they’re being sanded after the peel ply comes off or not, I’ll be lightly sanding mine to get rid of some resin build up in a few areas that had wrinkles in the peel ply. Next go I may use a lighter glass underneath the Soric and 4oz on top.
I’ll have to ride this thing to actually get a feel for the flex of it. I did not want it to feel like a ping pong ball eps/epoxy board and I can already tell it won’t. It’s hard to say how much of the stiffness came from the carbon rails and how much is from the Soric as I didn’t really test the flex before I infused it. I do feel that the carbon may have been overkill. A better option may be to put in a stringer and leave out the rails. But I also like the idea of having more flex down the rocker line than the rail line. Really I’m just going to have to do it both ways and see which I like better.
another thing I didn’t take in to account is if the Soric adds any notable volume as it is 2mm foam.
Interesting. I suppose it would be possible to only have the peel ply where there is flow mesh. I’ve heard of guys who build composite airplanes not using peel ply on specific parts to save weight. Mostly because they are shooting for the driest weave they can get without sacrificing strength.
Good job for a first attempt. You must always keep a “fiber only” part between inlet and outlet spiral tubes (no infusion medium either) to avoid resin getting too quickly to the outlet. Infusion makes resin-rich parts because even if your part is under vacuum at the beginning, you are letting resin at atmospheric pressure penetrate your part, so you lose the compaction you get with standard wet vacuum bagging. I did not use lantor Soric even in the Low Resin Consumption (LRC) variant because the data sheet states a quite high weight once impregnated with resin (470 kg / m3) as it sucks 800 g per m² of resin for the 2 mm version, plus the dry weight of the product… The upside is that you layer everythiing dry, take the time you need, prepare everything in advance and once ready, you mix resin, open thee inlet and watch… very interesting method but not light in my experience even though you can get reasonnable results.
soric is made to be a resin media flow for infusion, put fiber soric fiber dry in one shot all in bag, vacuum then infuse all in one go. i only do small flat panel like this to try, ended clean but soric textured. for same weight i like more use wood and thinner panel… carbon on rails, if you don’t go too far on top and bottom don’t give so much stiffness. stiff material far from neutral axis give overall stiffness so top of deck and bottom.
heavier is the board less stiffness is critical for feeling. a light flexy board can feel nice but buckle easier than a stiffer one. it’s hard to do a board flexy and buckle resistant…
A peel ply resin break between the board and the vacuum line would help the board fully infuse before the epoxy hit the vacuum line. Also better placement of the lines. Because I ran both lines wil spiral tubing the length of the board, I ended up with a slight indentation where they are. I’ve heard you can put the spiral tubing in and pull it from the surface of the board, then move it down lightly once vacuum is pulled. This way it won’t dent the foam. I may use 2oz or even 1.5oz cloth as the base layer next time. I don’t know if it’s necessary to have 4oz as the base layer and the weight savings would be nice.
