Let me say first that I have been searching for a while and I cant really find the information im looking for.
I did the top and bottom lam on my first board yesterday and today i went to takle the hotcoat. Used about a 1/2 qt of sanding resin, not sure how much catalyst I put in since it was from surfsource.com and it came in a little squeeze bottle and the intructions said how many drops to put in instead of other measurements.
My Question is how long does it take for it to completely harden generally. The extra resin I had im my bucked hardened in about an hour I would say so im assuming it is the same on the board but the thing is there is a remaining gooey film on top of both the board and the hardened resin in the bucket. Its been likt 3 and a half hours since I applied the hotcoat and im beginning the get discouraged.
I should also add that this is the second go-round on the hotcoat. I applied it once and realized after some time that I didnt add near enough catalyst so i squeegeed it all off and started over.This probably wasnt the right thing to do but whats done is done and everythings a learning experience. Any help would be appreciated.
yeah, sounds like not enough catalyst, altlhough the gooey extras sound like it wasnt mixed thouroughly. you’ll know when it is catalysed when you mix it, it turns more green than the blue it comes out of the jug. ambient temperature plays a role in kick time also.
Howzit rss, Where do you live, You can get a hygrometer to measure the humidity in your shop and when it gets past a certain point don’t hotcoat. About the only process I don’t do when the humidity gets past 90% is laminate since the blank is absorbing the humidity also. I know this may not sound right but here on Kauai we have been known to get some rain and I actually have seen my hygrometer go past 100% which still boggles me. Another thing to check is if the board is hot, one of my shapers glassed a board here a couple of weeks ago. Prior to hotcoating the board he had it in the sun( can’t remember why ) and he put it in the shop and did the HC and the wax didn’t rise so it was gummy time for him. Never hotcoat or gloss a board when the surface is to warm, if you have to you can rinse the board with cool water and take it inside and dry with a clean rag or paper towels, works for me.Aloha,Kokua
In answer to the original question, I’d suggest that if the remains in the bucket went off, you’re gonna be okay. If in your situation, I’d take it out for some bright sunlight, since the heat will accelerate setting.
Get, and use, a catalyst chart, showing for each typical amount of resin, how much catalyst to use for what percentage. I have seen it written that about one percent is the strongest ratio, but I note that this gives a pretty short pot life.
What’s kinda nice is the drops/cc/fl.oz part- and given this, it’s not an especially big deal to figure out how much to use if you don’t happen to have the appropriate measuring stuff handy.
Hot coats if not completely understood can be tragic, besides having a berometer to check humidity, there are many more variables, resin tempereture, weather,draft, a bad surfacing agent to catalyst ratio etc. When properly done a hotcoat should kick in about 10-15 minutes. In production they are used to hotcoating up to 6 +boards with one batch of hotcoat resin. If I am doing one board I really feel the weight of the resin (after you have done quite a few you know exactly how much you need) than I usually kick my hotcoats about 10cc for shortboards , 15+cc for longboardrs.I use 15cc surfacing for shortboards and 20ccfor longboards. Trick is it has to be nice and cool (not cold not hot ) for a hotcoat to cure proper. Too hot your wax wont rise too cold your resin wont kick . There is no way around this ,buy a heater, or a.c. do what you got to do . Anyway I mix my resin , let it heat up in the pot for about a minute than I paint the board , finish off w/light strokes than walk away, you should do your lay-up quite quickly, the faster you can walk away the smoother your hot coat becomes. As far as the question about how long your kicktime should be , I would say gel time 20 minutes - hard kicked a couple hours. good luck Ross. Petey
My Question is how long does it take for it to completely harden generally. The extra resin I had im my bucked hardened in about an hour I would say so im assuming it is the same on the board but the thing is there is a remaining gooey film on top of both the board and the hardened resin in the bucket. Its been likt 3 and a half hours since I applied the hotcoat and im beginning the get discouraged.
http://www.swaylocks.com/forum/gforum.cgi?post=215927#215927 The resin in your bucket should gel a little quicker than your hotcoat because of the volume of the resin, but not that much quicker. Check the link. The hardening time to gel time or vise versa is a ratio. The longer the gel, the proportionally longer the complete hardening time. You can always reHotcoat with hot sanding resin, and after it mixes with the cold hotcoat, should make it go off faster. Just don’t cut yourself short. A little extra sanding, so what. From now on, guage your MEKP percentage from the gel time in your ambient temperature (this is very important), whatever it might be. Use test batches to pinpoint the exact ratio. I glass in an average temp (during the summer) of 95^ and 70-80% humidity, and use an average of .4% - .5% mekp to get a gel time of 15-20 minutes for a lam, and a tad hotter for a gel time of 10-15 minutes for a hotcoat. Obviously your mixture and results should be somewhat opposite from mine. I was just trying to give an example and a point of reference. Good luck.
did you use Sanding Agent for you Hot Coat at all? Because it doesn´t sound like you did (maybe you just forgot to mention?), but it´s a must to get a tacky free, sandable surface!
Can I still revive the board or will the wax from the failed hotcoat make it difficult for another layer to adhere?
Quote:
Hey Ross,
did you use Sanding Agent for you Hot Coat at all? Because it doesn´t sound like you did (maybe you just forgot to mention?), but it´s a must to get a tacky free, sandable surface!
its premixed sanding resin from surfsource so im assuming that that step has already been done.
By the way, DOC, thanks for that chart, thats a big help, and thanks to everyone else too for clearing things up, now i just need to figure out how to make my board hotcoat-able
Howzit rss, The cool water is just something to do on very hot days before you hot coat.What you are going to have to do is hand sand the board just enough to remove the waxy surface and then rehot coat. The other day I was getting ready to do a hot coat and at the last minute decided to add some more S.A… So I did the hot coat and walked away since I only have the 1 board in the shop due to my upcoming cataract operation. Well the next morning when i opened the shop I noticed something was not right with the hot coat,Duh in the confusion of adding more S.A. I for got the catalyst( Yes even I make mistakes) so I just mixed up a new batch and rehot coated the board over the unkicked batch, no problems except now I will have to do some extra sanding on the deck.Aloha,Kokua
Thanks youve been a big help, I just want to clear something up.
Its not like the board is tackey, its got a gooey film, so do i just squeegee that off untill i can sand or are you suggesting that I sand whats presently on there.
Also, Ive been doing research on here for quite some time now and I always notice the howzits, what is that?
Howzit rss, Now I'm a little confused, I trying to see the problem in my mind . If it's a gooey film that you could squeegee off I've never encountered it before. Even if you didn't use enough catalyst it would have hardened by now since it's been at least 1 or 2 days. Alos if it's not hard you can't sand it so you might be able to do what I did and just rehot coat and you don't have to squeegeeanything offsince the new hot coat will blend in to the old one. You may end up with some lumps or bumps but they will get sanded off later. Howzit is a form of hello we use in Hawaii.Short for how is it.Aloha,Kokua
I just want to say thanks to everyone that helped out.
I just went out to the garage to check on things and its lookin good. THe deck seems to have fully cured to the smooth waxy way it should be, and the rails are almost there too. I think my problem the first time was a combination of the humidity and not enough MEPK and i also had a fan blowing in my garage. I was really starting to get frustrated but now im pumped to finish this up and go surfing. Thanks to all