Making my 3rd board and for whatever reason I wasn’t thinking and measured all of my epoxy incorrectly. I was supposed to measure the hardener at .44 weight the resin. Instead, I did all of my calculations at .44 the amount of OZ I was trying to pour. For example, if I wanted 25oz of epoxy, I would pour 11 oz of hardener (.44 of 25) and 14 oz or resin, rather than by the weight of the resin. Ok, big mistake and yes I am an idiot. I am not sure what I was thinking but I did all of the calculations at one time so never caught it. Anyway, its done and I have a completely glassed board…
Board is dry. Its not tacky or sticky. However, it feels slightly softer than my other boards when I press on it. Maybe more rubbery is a better term. I’ve notice some of the strands on the ground that I had cut off during glassing bend and don’t break. The deck and bottom feel like I am going to pressure ding this pretty easily. I can press in with my nail and make a mark but when I tap on it it feels solid. It looks solid. Rails, fins, leash plug feel really solid and they are fine. Its been sitting in my garage for 48 hrs curing at well over 80+ degrees and this is the result.
Any way to salvage this? I was thinking I could just leave as is and hope for the best, add a layer of fiberglass to the deck to help with pressure dings, sand and re hot coat the board, or reglass the entire board by stripping the glass and redoing it. This is a fish for under chest high waves, boards for me personally, and I only paid maybe $225 for materials so not the end of the world here.
Foam is already softer than a FG layup, so “soft” isn’t a problem if its covered by “stiff”. Heck, you might even like the ride a little better, I think you’ll be fine if you just add another layer as a deckpatch and (to stabilize the fin system) another for a fin patch. If you don’t do a full layer top/bottom then finishing the softer lam will probably be more difficult.
If it were my board I’d just do a full layer of 4oz. But then again I’m notorious for overbuilding boards. If you’re doing a traditional style fish then those tend to have some additional weight anyway - helps with the glide/carve.
First off, you have about 44% hardener, by volume, 56% resin. Just how far off is that from the manufacturer’s specs of measuring and mixing by volume? Some are 50:50, some are 2:1, some are 3:1 and so on. Chances are you were pretty close. Look up the specific gravities/densities of your particular epoxy (the MSDS sheet will have it) and hardener and find out. If they are pretty close, and most are, fine. It doesn’t have to be that damned precise. You’re not making pharmaceuticals here.
Or don’t sweat it. It hardened after a fashion, and it’s only been curing for a couple of days. Give it a couple more. Some of the it feels soft may well be because you expect it to feel that way, having discovered your mistake you went looking for something wrong. This is why they have, for instance, Rockwell testers for metal hardness instead of bashing it randomly with a hammer.What it feels like isn’t all that accurate unless you havs something else to compare it to and a very sensitive thumb.
Don’t strip the board. Really. I mean it. Lightly sanding. the hot coat and adding a deck patch, sure, if you want to. Probably a good idea on a fish anyhow, those get stomped a lot in use. Sanding away all the hotcoat, and redoing that, no. Leaving it alone and letting it cure further is probably fine too.
Oh, and get a gram scale (1000 grams capacity, at least) , with a tare function. Store it on top of your epoxy resin, so you have to handle it to get at said resin. One of these, for instance.Mostly for your peace of mind.
If its any consolation you’re not likely to do it again and you’ve done one of three (too much hardener). The other two IMO are not enough hardener and not mixing thouroghly enough. Have done all three with epoxy once and never again.
Give extra cure time,maybe add 2 oz cloth per side…
My math isn’t that good (Florida schooling) using resin research epoxy,but I go 2 to 1 on a digital scale. I use a heat pad in a cooler to warm the resin up.mix in a measuring cup to double check myself. Mix well for 2 minutes slow…99.5% success rate even in colder weather …easy PZ ,just some food for thought
Thanks all. Going to head down to the local shaper warehouse on Monday when they open up and pick up some cloth and hardener.
Its supposed to be 80+ all weekend so just letting the board cure. As far as the volume, it was a 2:1. For weight, 44% for each 100%.
Also picking up a new digital scale. I do have a postal scale but its super annoying - stops like every 4 seconds to ‘lock’ the weight. I want to smash it every time I use it for anything.
Place cup on scale, zero the scale. Now all you're measuring is your mix
Part A: fill cup with 10g of Part A.
10g / .56 = 17.8g, rounded to 18g - that's the only calculation you need to do.
Part B: Add Part B until you hit 18g. Mix well .
I use condiment bottles for mixing small quantities. I use wooden paint stirrers, cut in half so they won’t tip the cup. I wipe those down with paper towels. Heck, I tear the paper towels in quarters before use because that’s all it takes to wipe a spreader or a stirrer off. I buy cheap plastic drinking cups @ $5/50. I’ll reuse the cups a few times after the prior contents have hardened - there’s no reason to even clean them (so no use of alcohol or vinegar for cleaning them) because when you zero the scale you’re still only measuring what you’re mixing/using.
VERY little waste of either resin or consumables so long as you figure out how much resin you need for what you’re doing. You just about can’t screw it up.
A cheap digital scale will pay for itself in saved wastage in just a couple boards.
Man! I eyeball everything. Resin Research. Mostly Quick Kick or Fast. Haven’t had a problem in a long time. Don’t have a scale, but probably should get one in my next Uline order. My fear is that if I start getting more accurate, I’ll start having problemas. Sort of a “If it works, don’t fix it” situation…
Update: Board is done. So much better. I put 4oz on the both the top and bottom. Also bought a new scale. Looks like I am getting some waist to chest high surf over the next 4-5 days too so I can test it out!
This was board number 3 for me. Looks way better than my first two even with the epoxy issue. I have a feeling my next is actually going to be good.