My first surfboard repair - (WIP)

[IanCaio]

Lesson number, well, probably 100 so far:
Triple check what you need to order online before buying. I just received my fiberglass cloth, and realized I need to buy styrene monomer and wax solution (aparently I can't sand the fixes without wax, can anyone confirm?). Now I need to make another order to deliver.
Cost of mistake: 15 bucks.

Since styrene monomer (which seems to be used to avoid bubles in the resin, in really small quantities) is a resin solvent, can I use it instead of acetone?
And about the wax solution, is it really obligatory or it just makes sanding easier?

And Billie, thanks a lot for your tips, they were really useful!

[oldmansurfer]

Where I live you buy the resin with the additives already in and they are sold as laminating resin, sanding resin and gloss coat. I don't know what the various additives are but I think the wax is added to make the resin not tacky for the finishing coat and you don't want bubles in any of the coats but don't quote me because I never had to mix anything other than the prepared resin and the catalyst (or for epoxy 2 epoxy parts)

[IanCaio]

I bought polyester resin in an automotive paint store, so it's not actually a specific mixture for board laminating and coating. Maybe for that reason I need the wax.

I heard exactly that; wax is supposed to make the resin less tacky. Maybe it's not primordial, not sure if you can sand it when it's tacky, or even how tacky it gets. It's the sort of thing I'll only know when I actually use the resin. But the brazillian guides and videos I found all mention those 2 additives (styrene monomer and wax solution). And even a guide in english (http://www.surfersteve.com/hotcoat.htm) mentions the wax, no word about styrene monomer though. Guess it's just a solvent, that helps the resin not producing bubles because it reduces viscosity, but I believe it's optional (people say you should use really little, or it will dissolve the resin).

Epoxy resin don't require wax (point for them!) but are harder to find around here and more expensive.

[oldmansurfer]

Hahaha well....Thanks for posting that. I never knew the difference between the resins but investigated a bit and found this easier description http://jfmill.home.comcast.net/~jfmill/dings/dingdex.html

[IanCaio]

Glad to hear it helped you!
Really cool link by the way, lots of good info. Been reading some of the questions here.

Just gotta be careful not to use polyester resin on EPS boards, it eats through the foam. Epoxy is compatible with both PU and EPS boards.

I was thinking about using superglue to fix the fin in place before laminating. Never seem people using it though, so I'm a bit worried.

Tomorrow I'll buy some spray paint to finish the board, and I will have everything I need to begin working (hoping the wax solution and styrene monomer gets here tomorrow). Then the fun part begins

[waikikikichan]

Superglue eats styrofoam/EPS.

Did you get Acetone ?

Did you get Fiberglass rope ?

Do you understand what they mean to squeegee out the saturated cloth so the fiberglass doesn't "float" ?

Will you do trial test batches in the resin cup, to see how long of a working time you got before the resin "goes off" ?

[jaffa1949]

I would if it all fits together forget superglue, make arough estimate of how much resin will be needed in the fin box with the fin inserted, extra won't matter because as you force the fin in the extra will come out then apply rovings? (what are they ?,a whole set of loose fibres, maybe teased from that fibreglass rope) around the fin base into the excess resin align them nose to tail and build a pretty mound that looks fluid dynamic around the fin extend the fibre out beyond the fin base all round.
Wherever you want your resin to grip existing glass you will need to have sanded awat any gloss coat and roughened the surface,
Your fin roving mound probably doesn't need to be as big as a fixed fin set up because the strength of the box will help the fin.

You have been saved a real difficult step with the box, ( assuming that had been done correctly) the step of aligning the fin both perpendicular and without any toe in.
for a fixed fin set up you had to become the master of masking tape bracing.
enjoy the process.

[IanCaio]

Waikikikichan,
The superglue would only touch pieces of carbon fiber (fin+fin box), at most it would be in contact with resin. But my board is PU anyways. I was more worried about incompatibilities with the resin, but it doesn't mention polyester as incompatible in the label of the superglue.

I didn't get acetone, but I got styrene mononer, another resin solvent.

I didn't get fin rope, but I plan on making one out of individual threads of the fiberglass woven, sort of a fiberglass pigtail.

I do understand I can't leave the fiberglass saturated, and it should make a "zip" sound when scratched. Thank you for making me understand better why though: by "float" I guess you mean the fiberglass could stay in the resin but not entirely in contact with the surface. I can imagine it would be trouble.

I will have to fix some minor dings before laminating the fin, so I should have an idea of how fast it gels and hardens until then.

Jaffa
For sure, I have been pretty lucky that the fin still fits its place in the box!
It will make the work much easier then if I had to glass it on the board itself. I don't have roving, can I use threads from the woven instead?

[oldmansurfer]

For your rope replacement, you don't need to weave the fibers just make sure they are all parallel. I just used to use them loose but in the video it looks like they tied one end and worked from the other side. If you actually had rope you would have to unravel it. You want to be able to shape it to smooth out the contour between the fin and the board. A woven rope won't do that. the long fibers will add strength to the resin that goes in that space. resin is very brittle which is why they don't just coat a board with resin (which would make it much lighter)

[IanCaio]

So I could only take the threads parallel to each other and use them loose? I will take another look at the video you posted!

The rest of the materials arrived, gonna start working tomorrow

Wish me luck!

[oldmansurfer]

Yeah I held it like a bunch of hair and used it like that but in the video they had the one end tied so that it stayed together without having to hold it but you want it to spread out a little so don't use the tied end.

[IanCaio]

Little resume of my first day of work (my hands are still a little sticky):

The first day is always the one with more mistakes. I decided to start sanding the crappy fix the shaper who sold me the board did (shame on him, lost a potencial future client). I evened it out as much as I could, looks like he used 8 oz cloth or something. It's alright, always good to have extra resistance on tail. It looks way better now that I sandened it.

The weather isn't the brightest, so I decided to only fix the two minor dings (the one near the fin cup, and the one over the "EFEX" patch). Made a mixture of resin, styrene monomer (there were several bubles, so it seemed nice to make it less viscous) and wax solution. Then I realized I forgot to tare the scale to weight the resin, had to guess how much catalyst to use. Since it isn't really sunny, I putted 10 drops (it says about 20 to 40 for 100 grams, it had a little less then 50 ml, was more of a guess in the dark). Putted it in the bottom of a cutted soda bottle and used a pencil to cover the areas with resin. After a few minutes I went to see how hard was the resin left (needless to say, I didn't use 1/4 of the resin I mixed). It was hard already, and with a wierd purple color (unlike the resin on the board). It was a little hot too, maybe I over counted the catalyst (I'm almost sure I did ).
By the way, I'm thinking to wait until tomorrow before sandening it, is it a good curing period?

Had fun already, despite some trouble related to not having a completely prepared workspace, but I had some ideas to work better next time.
Man, those resin and fiberglass dust itch. Gotta take a shower.

And another note, cirurgical gloves are kinda crappy for the job, not sure if those big thick gloves are better. Gonna have to keep using them though, paid 30 bucks and there are like 100 gloves on the box.

Some pictures below

[IanCaio]

Another question I forgot to make: how do you discard the resin, solvents and etc? I don't think you can simple throw them in the sink, was thinking about storing them on a bottle until I figure out what to do.

The pencils would have to be washed in the sink though, but it would have less material being discarded.

[oldmansurfer]

Make sure you remove the tape before the resin hardens completely

[oldmansurfer]

If I were going to dispose of resin I would mix it with catalyst and after it hardens then throw it in the trash. What I do now is put it on a shelf in my room One day should be good. It depends on the mix if it is no longer tacky at all you can sand it.

[oldmansurfer]

I once helped a friend make a surfboard and he was really impatient, he wanted to use it now!!! So we put the sanding coat on the board and he made it extra hot (mixed a lot of catalyst in it) then he set it in the sun and we left for a quick bite to eat while the board hardedned. I told him I wasn't sure about doing either of those things and then leaving the board alone but he said it would be just a half hour or so while we get lunch so "What could happen?" We came back to see smoke pouring out of the garage where the board was. His board was on fire. We put it out and he had to repair it and it took another few days of work till he could use it. I guess because he had to reglass an area on the deck and he aquired a pot leaf, he glassed a marijuana leaf into the deck of the board and then had to rip it out because he would have been arrested for possension according to the cop who stopped him. That was the worst looking new board ever

[IanCaio]

Man, I runned as a crazy when I read your message to take the tape out. Thankfully almost no tape had resin over it, guess it's fine. Took it all out, the resin is hard, but I think it is still between gel and completely off. Don't want to risk sanding it now.

I am mostly worried about discarding the solvent, since I use it to clean the material I have to discard it properly.

The worst scenario I could imagine on this fix is to suddenly find my board on fire, thankfully I didn't use that much catalyst .
Guess besides the small troubles, it all went fine today . Hoping for a sunny day tomorrow, so I can keep working.

When I sanded the board, the resin and fiberglass dust felt inside the fin cup (picture below). If I wash it with water I'll have to wait the board dry in the sun again. Could I blow air in there and work later without washing it since it's only resin and fiberglass dust?

[oldmansurfer]

I imagine air should work, try it and see.

[oldmansurfer]

Besides the resin hardening over the top of the tape if it get under the tape and hardens it may stick to that bit of tape too making you have to sand it out

[IanCaio]

I guess if there is a minimal piece of tape it is in the border, so it would be easier to sand out.

Weather is not on my side, it just started raining. I got my board protected, but humidity is definitely high right now. My luck is that the resin is hard already, not sure if 100% cured though.