dj, here is what Greg wrote to me when i asked him how much i need to do 4-6 shortboards
“Three gallons should be ample unless their longboards. A three gallon set costs $153. That’s a packaged material price and the costs in larger quantities are more reasonable if your doing a production in epoxy. It really has about the same costs because of how far epoxy goes compared to poly.”
He also gave me approxomate amounts of resin to use for top and bottom laminations + hotcoat
6’ and under - 9 -12 oz. bottom 12-15oz. deck 7’ and under - 12 -15oz bottom 15-18 oz. deck 8’ and under - 18 - 21 oz bottom 21- 24 oz. deck 9’ and under - 24 - 27 oz bottom 27- 33 oz deck
Hot coats run just a bit more than an ounce per foot. For instance a 6’ board would take about 7 oz. per side. Longboards, 9’, take about 12-15 oz. per side
What does this this mean ? Is that fluid ounces(volume) or does it mean ounces by WEIGHT??
A bit confusing for me cause we usually use metric system in Europe
Sorry for our American backwardness. It would make so much sense for everyone to be on the same page. Those are ounces by volume. There are 30 ML in a volume ounce.
Lamination with epoxy is a dark art, it depends on the individuals tolerance for time, motion, cadence, etc, etc. If pushed I can laminate the bottom of 9-6 long board with the equivalent of 1 beer can, and the top with approximately 1.75 beer cans. So the average mortal man should use 1.25 beers for bottom, and 2 for the top. I never spill a drop of epoxy on the floor, and there is nothing left in the bucket. Your mileage may vary. Also if you need more resin, just mix up a small batch pour it on the board and get back to work.
That link to Greenlight’s resin chart is good. Without getting in to a bunch of BS about “I only use THIS MUCH per side” or whatever, it (the chart) definitely works for all length boards and all kinds of cloth weights (or combination of cloth weights) to calculate lamination amounts based on a basic multiplier X weight of cloth. I’d say the fill coat and gloss amounts on the chart are pretty accurate as well. Somebody went to a lot of work to figure all that out. You might as well use it. Skip the math and pay attention to making sure you have grabbed the correct bottle of epoxy or hardener when you are pouring. Mix well.
I rarely have ever purchased a 6 oz or another specific ounce roll of fiberglass that matched the true weight of the cloth, which is printed on the side of the box the roll is shipped in. It is usually always under the stated sold as weight. This varies from roll to roll. It is also very cool when asked if you did a double 6oz on the top and you say “no, it was a double 5.73oz” Some overseas manufacturers do not document true weight of cloth also.
I can pretty much look at what needs to be glassed and mix up the correct amount. Not enough mixed up with the initial lamination for me personally would be a fail. Filler coats and final coats you can easily mix up more if needed because those coats are brushed on. You will eventually get good at estimating without charts after a few different length and width boards one glasses
I rarely have even a cap full of epoxy left in my bucket. and I can estimate the exact weight of cloth down to the .005 oz. Building a surfboard is a exercise in exact science. Fin foil, rail design, plan shape, glass weigh all need to be to thought out months in advance with advanced calculations. 2/x4 (3x7) / 2(2342.2342 x 34234) /231453. Use this formula and you will get the exact epoxy calculation. No body likes a sticky floor.
Did I mention that I laminate in my living room…and I have shag carpet.