Done airbrushing (very tricky)I now would appreciate some advice on epoxy laminations.
I’m going to laminate my shaped xps blank with SP systems (From the UK) 115 low viscous epoxy.
The board is 5’10" x 20" and I plan on using one layer 6 oz on the bottom and 6+4 oz on the deck plus some patches for Red X boxes on the deck and bottom.
1 How much resin should i use for the bottom and deck respectively?? I’ve done some smaller lam jobs before so I’ve got a little experience.
Ive read in the archives here someone suggesting 3/4 lb for a 6 oz lam doing a shortboard. Is that correct?
Can I or should I use PU varnish for hotcoating?
How about using PU varnish if I want do a gloss coat?
I’ve read “epoxy wiz” Greg Loehr suggests using a plastic squeegee, couldn’t find one in the shops around here what should it look like?
Greg’s Post about how to use his epoxy resin. It has amount for different sized boards. I think it would be a good guide for any epoxy resin but you may want to go with a little extra resin than he states just to be sure. Also if you want, type in Greg Loehr / epoxy lamination in the search of the archives and you can “read until your eyes bleed!” or until you are an expert on epoxy lamination.
A varnish will not work for a hotcoat - you need to use resin - to fill in the weave after laminating to get ready for sanding. Epoxy can be a nightmare to sand if you do not have the right stuff. Greg has his Additive F. See if your supplier can recomend any kind of sanding additive to your resin (or ask if your resin already is formulated to be able to sand).
You need to sand the board so it is ready to ride and then you can put on a varnish. If you use the right stuff and know how to do it, you can buff out a varnish to a mirror shine gloss.
The plastic sqeegee is just a plastic drywall spreader. Most hardware/paint/fiberglass stores should have them.
Here is a repost from a while ago. Hope this helps.
Mix ratio must be adhered to. Deviation from the mix ratio will keep the resin from attaining a full cure. Also the material must be THOROUGHLY mixed. If not there can be soft spots. We use metered buckets (available at most hardware stores) to assure proper mix. We use large paint stir sticks (like the ones hardware stores give you to stir paint). All our resins are 2 to 1 mix ratio by volume. The metered buckets work unreal, actually better than pumps and we laminate right out of those buckets.
Additive F. We use it in every batch we shoot, including laminates. It eliminates blush which is the biggest problem in building epoxy boards. It only takes 1cc per ounce of hardener in the mix. We put it in after pouring the resin and hardener into the bucket and then mix them all at once. It makes the resin a bit cloudy but clears out when the resin cures.
When laminating, the first thing to do is to pour all the resin out and spread it over the glass. You then wet the rails and tuck them. This gives the resin time to soak into the cloth on the flats. Polyester must be pushed through the cloth. Epoxy just soaks in and it does that in its own good time. It can’t and shouldn’t be forced. Additive F actually helps with this quite a bit. After it soaks in, squeegee out any air and remove any excess. We use plastic, “spreader,” type squeegees. We’ve found that they move epoxy better than rubber squeegees do. They take a couple boards to get wired but after the initial learning curve laminating is much easier.
We use VERY little resin. Below is an example of our use levels for different size boards. As there is no “gel” time, any resin left over can be used on the next board. If you run short you can easily mix up additional resin to finish with. Usually we just work out of one bucket and simply keep mixing more material as needed. It isn’t the same, “this bucket for this board,” as polyester. These are estimates for total mixed material.
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. If your glossing use a bit less than a hot coat. We use 3" disposable white bristle brushes for hot coating. We don’t clean them. We use them for one batch and pitch em. Not only do we feel that their not worth cleaning but we’ve also had problems in the past with contamination from cleaned brushes which manifested itself in bad hot coats. New brushes always make for clean hot coats.
Do not use acetone for clean up and never let contaminated acetone touch the skin. Any toxicity problems we’ve seen in the past always included contaminated acetone. Not only that but acetone doesn’t work that well with epoxy anyway. Leaves everything sticky. For your hands use disposable vinyl gloves. Clean gloves between boards with scrap fiberglass. I usually cut scrap and pile it neatly on the table so I have plenty ready. Clean your squeegee with scrap glass. Anytime the squeegee gets slick I just wipe it and my gloves down. When the gloves get funky, peel em off and put on a new pair. 10 cents a pair is cheaper than acetone. With so little resin being used very little goes anywhere except on the board so things tend to stay much cleaner. We don’t ever get more than a drop or two on us. If you do get some on you, use Go-Jo or Fast Orange or some other waterless cleaner with water to get it off. These clean epoxy more effectively and are much safer to use than acetone.
I have a pair of scissors I use just for laminations, close at hand or in my back pocket for trimming all of the loose strands before I lap the rails. They go in the bucket with my squeegee at the end of the lam session. Avoid any plastic handles, acetone will melt them.
Correcto, sorry for the confusion. Nary a drop of acetone in my epoxy glassing bay. Little if any solvent, 'cept some denatured alcohol for a sparse rinse of the squeegee and scissors. Any spills on the skin are wiped off with cloth scraps and a GoJo orange oil wipe.
The mention of acetone above was in the context of polyester lams. I don’t miss the styrene or acetone, kind of avoid poly ding repairs if I can. Thanks.
I know that the top consideration when working with Epoxy is temperature. I think I’ll get less off gasing if I laminate when the temperature is dropping, so that’s what I’m planning on. I have to pick a primo day, cause I don’t have a nice 73 degree controlled environment to work in. If I can get constant air temp. that’ll be great.
I’ll be going with futures on the 6’4"x18.5" from super light clark blank attached so they’ll get put in first of course. I’ll do them the night before I laminate the board.
I’ll be doing my laminations outside and pretty much baby sit the whole process. The air temp is 60 to 65 degrees, which is the daytime norm here in Santa Cruz, what kind of prep should I do so I get a good solid lamination and not have to do more than a couple of back flips to get there?
I’m figuring on putting the resin, hardener and “F” in a 75 degree environment the night before I do my laminations.
I’m thinking that each side will take about 40 mins to an hour to be ready go flip if the temperature is around 70 degrees but if it’s cooler I might have to wait a couple of hours. I’d like to hot coat while the board is still a little tacky so I don’t have to sand the weave. If I have a little alcohol around to dip my gloved hands into before I touch the board with this help to keep them from sticking to the board?
I’ll shoot one side and then flip it and get the tape off as soon as the epoxy is stiff enough that it’s isn’t dripping off the tape along the rails any more.
The idea is to get to each side while it’s still tacky enough so the whole process can happen without any sanding along the way. I’ll let the board cure for at least a day before I sand to 400 and seal.
Do you think I can pull it off?
If there are bad ideas here let me know cause I really don’t want to hack it up too bad.
I’ve hotcoated after a few days without sanding, I just wiped it down with methanol. I’ve had no problem so far with the hotcoat peeling of or chipping anything. From what I’ve read it’s partly the amino blush and the smoothness of the epoxy surface that make epoxy not stick to epoxy. If you’re using Greg Loehrs epoxy the amino blush should not be a problem. Greg Loeht told me the (m)ethanol etches the epoxy which should take care of (some of?) the epoxy smoothness. I usually leave the board for atleast a day before I do the lam on the other side since I’m using a generic epoxy which takes a long time to be tack free enough to flip. Besides, if I was to wait for 70F airtemps outside I’d have to wait for a change of seasons to lam. I’ve noticed that the epoxy is a bit sensitive to heat, but even at lower temps it will eventually harden(even if it takes days and end up more flexible).
If you could lam in a more controlled environment(heated, indoors) I think that’s safer. Also, have you considered building an insulated box to put the board in together with a heater after glassing? It’s certainly on my todo list.
If you do not have a heated area, prepare to do one stage of glassing per day. It is very temperature dependant. If you glass in 75 degrees, it will cure ready for the next steps in a couple hours. The first time I used Epoxy (ResinResearch fast hardener w/ Add.F) was in 60 degree weather outside in direct sunlight. It took all day to cure hard. I thought it was ready to flip and cut the laps after a few hours because it felt how a poly lamination felt when it is ready to flip. It was not ready to flip and the cloth stuck to the tape when i pulled it off the rack after flipping it. I was very bummed, but to my surprise, i pressed the bubbled cloth back down onto the foam and it stuck - no worries. Moral of the story - be careful not to flip the board too soon, epoxy seems to be ready to mess with when it is tack free - if it is still tacky at all it is not ready. You can help the cure time by heating the resin up a lot more than 75 degrees. Put it next to a small heater untill it is warm to the touch and mix it right next to the heater (this helped with my 2nd lamination and hot coats). Even with the fast hardener and heating it up, you will have NO problem with it going off too fast. The stuff takes forever.
One more thing - the epoxy really adheres to the tape (unlike poly) so be careful cutting the lap. My first lap i cut, it cut smooth and easy but i looked at the lap and a sliver of the tape was left under the lap - doh! - and it was near impossible to pry it loose. With poly, the tape will just kind of slide away even after a full cure. For the other epoxy lap, i buzzed the lap at the tape line with a grinder, then i folded the tape over itself to hopefully get a nice crease to cut, but to my surprise, it just peeled right off, perfect clean line with no tape stuck to the board and i didnt even need to cut it with a blade!
I have only done one board in the epoxy so my experience is limited, but hopefully this helps some…
I’ve been here since '68. Now that you mention it I remember Hoy surfboards, but I haven’t seen any of his boards in a hell of a long time nor do I know what happened to him. I never met Tom. One thing for sure is he wasn’t afraid to try something new. He made some real thick radical boards and some with exaggerated, what I call elf shoe, nose rocker as I remember. It was back in the day when the fin in the attachment I made yesterday for a glasser buddy of mine was often seen on those Weber Performers, which were among the leaders in longboard performance.
On the epoxy thing ~
So what’s the take on the best way to get a primo bond between lam and hotcoat without sanding between the two applications. Is there a trick that I need to know?
Is a methonal or ethanol wipe the way to go. Or should I hand sand real lightly with 80, 120 or 220?
The epoxy I’ve used, if recoated within 24 hours, does not require any surface preparation. However, that was on planes, and in a clean and fully temperature controlled environment.
I still do a light once over with a worn 80 grit on a block for laps, N/T tucks and just little zits in general. It can’t hurt and it saves that much more work after the hotcoat. I use a 6"x 12" piece of cloth scrap folded up into a pad, saturate with alcohol and wipe the whole thing down. The addtive F is supposed to eliminate these steps but for the addtional 10-15 min. it’s no big deal.
Cheers Rich, still working out some fins to run by you on the LB twin I’ve been riding.
yea tom rolled up here in about 75 i think ,definately the same hoy coz he still does the thickest boards you ever seen…with super boxy rails …
hes been in margret river the whole time ,i remember going into his shop when i was a grommet and coming out stoned on the passive smoke lingering around…interesting character ,basically just wanted to escape the rat race ,was disillusioned with the contest scene and the hype and hollywood ,so he just wanted to disappear …
also about the lam to hotcoat bond…
the best results ive had is to use the right timing …
i lam up a little drier …then hotcoat just when its hard enough to not move around on you and soak up your hotcoat ,but still soft enough to be tacky and except another coat ,
ive found a light sand beween coats isnt good enough coz it cracks off when the board gets knocked …
if you glass to wet so its shiny you can sometimes have troubles with the hotcoat if your timing is out …
so the drier rougher lam job seems to accept the hotcoat better and it gives slightly more leeway on timing …
all this will depend on which system you use…i reckon ive used about 75% of them and none of the ones that claim poly can bond even without sanding actually stand up to the test…