4 oz cloth is not very thick.
Lightweight Surfboards usually have just one layer of 4 oz, in reality 3.7 oz cloth on the hull, and no less than 2 on the deck. Fragile.
E cloth has the same thickness strands front to back as side to side, S cloth has thicker strands from to back and thinner side to side, and makes for a stronger stiffer surfboard for the same weight.
The same would be true on a skateboard deck
I like my short surfboards a bit heavier than most and much more durable.
I’d use two layers of 6 oz on the deck, and one on the hull, with big laps/ overhangs, and often more reinforcement where my feet would go.
I’d glass my longboards even heavier, and not just for durability, but for weight, and momentum, and style.
Take a Q tip/ cotton swab, and remove just enough cotton until it can be screwed into the insert. Take a little bit of car wax onto that de volumed q tip, and twist it into the interior threads of the insert, back and forth like a screw. Q-tip will likely come out grey or black. Repeat with new swabs until it does not, and feels buttery smooth.
Try not to allow any wax to spooge over the top as then it might compromise the bond of the epoxy saturated fiberglass. If it does spill over insure it is cleaned off with rubbing alcohol, but make sure alcohol does not get into waxed threads.
If any epoxy does get inside, then a dental pic can fairly easily clean the inserts interior threads of the epoxy.
I’ve never tried the hot glue trick, but I imagine the car wax would make the plug of hot glue easily unthread too. I’m gonna experiment with that before my next build. Thanks for the tip
Wrapping the cloth around the edges can have issues with bubbles forming depending on how thick and how tacky the initial layer is, and how sharp the deck’s corners are, and how thick the fiberglass is.
I just let my wetted cloth hang over the edge, no attempt to ’ wrap the rails’/ fold it over or even down, and then later when 95% cured I flip it, razor off about 10mm from the edge of the board, and fill that lip with fiberglass tow/ Finrope/ strands of woven roving, then glass the other side too.
95% cured as then subsequent layers of epoxy will still chemically bond, as long as the humidity was not super high. Amine blush can form and impede secondary bonding. Some epoxies claim to be blush free. BS. Humidity makes more blush more likely to form.
Blush Resistant maybe, If in Doubt, wait for 99%+ cured, then sand( with new sharp sandpaper) for a solid mechanical bond before attempting secondary bonding.
A perimeter of unidirectional fiberglass can form a semi transparent Halo, make the board a bit wider, stiffer, more waterproof.
I bought a large batch of 24 oz woven roving, and pull off individual strands. About 7 to 10 strands will add about 5MM perimeter.
I wet them out fully and squeeze out extra epoxy in a long PVC pipe cut longways on a tablesaw and Ziptied side to side so they cant roll, lift them out and lay in place working any bubbles from center to edges.
One thing to remember when laminating, is to pull the weave of the cloth tight from nose to tail before wetting, and try to keep the weave square/ perpendicular when working epoxy from center to edges. Dont push the epoxy around a lot using a lot of pressure on squeegee or paintbrush, it will form lots of micro bubbles. Slowly spread it over dry cloth with little pressure from middle towards nose and tail then towards the rails, and let it soak in at its own pace. Laminating with polyester resin one does not need to worry nearly as much about the micro bubbles, but epoxy dislikes being over worked with a squeegee/ brush and the result might look a bit cloudy, or worse.
If the weave is not pulled tightly, it will not reduce the flex as much as if it were.
A good surfboard laminator can influence the flex of the board by how tightly they pull the cloth, and it is one reason why two identical surfboards can feel so different underfoot and pro’s boards usually all get glassed by the same laminator and sanded by the same sander…
Uncured epoxy is easily cleaned from laminating tools with distilled white vinegar. No need for acetone, and never use acetone to get uncured epoxy off one’s skin
Try to keep uncured epoxy off of your skin entirely. Some people are so sensitive to the amines in the hardener, they can break out in hives immediately. Many will develop sensitivity with repeated use, and in some rare severe cases they will have reactions even with fully cured epoxy.
Those guys on Forged in Fire getting 5 minute epoxy all over their hands when gluing up their handles, are insane.
The dust from sanding epoxy is toxic until fully cured, inert after, but no dust is good to breathe.
Have some cornstarch to make getting gloves onto sweaty hands much easier, and double gloving can really save some time in the long run.
Use of masking tapes with ‘edge block’ technology like frog tape or similar for painting, will be regretted when working with epoxy, as will low $ masking tape.
Mixing the epoxy by weight, rather than volume is recommended. Mixing cup graduations are often delusional. My Surfboard laminating epoxy by 2:1 volume, is 100:43 by weight. Pour X amount into cup on zeroed digital scale, multiply X by 0.43, add that much hardener to the nearest 0.1 gram. Some are 100:44 or 100:45
Make sure the flat mixing stick can fit the bottom and corners of the mixing cup No round popsicle sticks please!
Make sure no epoxy drips down the side of the cup when mixing. Scrape all 5 sides of the mixing stick on the flat cup edge no less than twice when mixing, and the sooner the stick is scraped the better.
Mix until no ‘swirlies’ are visible under a strong light and it is completely homogenous, then mix a bit more.
When epoxy does not cure correctly, from either improper ratio, or incomplete mixing( or both), it is an absolute fucking nightmare. It is well worth it to make sure that the ratio is as exact as possible, and there is no chance of improper mixing.
I Cant stress this enough.
Even if the epoxy has a 5% room for error, and seems to cure OK, that 5% difference will ultimately affect the bond strength, and hardness and tensile strength of the cured epoxy, to some degree.
So Aim for perfection, even if it adds time and is a pain in the ass and people tell you they never bothered and everything came out ‘just fine’.
When truly fully mixed, get it out of the cup fairly quickly, or it will generate a lot of heat and start thickening prematurely. Pour into a wide baking sheet like container to increase working life before to starts to thicken, or at least have a wide clean pan ready to pour the excess into when one mixes too much and has too much to apply and its going too slow and the curses start flying.
Before cutting fiberglass, make sure the weave is square, and perpendicular and cut rectangles from inbetween the individual strands, to the best of your ability.
Don’t even bother trying to cut it with shit scissors.
Pull out a few strands from the cut edges as they will likely pull out anyway once wetted, stick to your hands and tools and make a giant mess and ultimately compromise the result.
Fiberglass tape is certainly easier to work with, but is really designed to be wrapped tightly around a cylinder. Laying it on a flat surface does work, but the edges of the cloth can become all warbly, and once that warble is sanded flat, those sanded strands which are supposed to be helping to reduce flex, are all compromised, somewhat defeating the purpose.
One other thing to keep in mind when laminating wood/ plywood, is the deeper that initial layer of epoxy soaks into the wood, the stronger the bond of fiberglass to wood will be. One way to insure deep penetration is warm the board and the epoxy up, and let it soak in as much as it can. There will be some areas of the wood which will be much thirstier than others and to best see these areas it is best to be able to look at it from all angles. If this is not done, really dry wood can heat up when the epoxy is applied, and actually blow bubbles.
I like using a fine pore 99 cent store Sponge, which I already washed with dishsoap and fully rinsed and fully dried, and basically force warmed epoxy deep into the warmed wood grain with double gloved fingers holding epoxy soaked sponge. Some areas will seemingly drink a ridiculous amount, and these same areas, if they were not allowed to drink would be the first to delaminate in use.