Hey guys, I posted this at the end of a thread further back so it might have gotten missed. I just ordered some UV catalyst to try. My thinking is I am going to use it WITH MEKP to speed things up a bit. I usually don’t get a lot of time so when I have it I need to be more productive. I want to let the resin kick …lam or hot coat doesn’t matter, so it is stable and then walk it outside to “cure” with the UV cat. Is this an OK approach? Not having any experience with UV catalyst I am wondering how long before I can flip, sand, recoat, etc…etc. I am under the impression it doesnt take too long to cure this way say 10 to 15 minutes as opposed to 2 hours minimum with straight MEKP. Is there any thing to worry about with the combo? Does anyone use this approach? Seems like the best of both worlds. I sure wouldn’t want to try to carry a drippy, wet board out to get a tan. Whoops…how about those custom grass blade/leaf/dog hair inlays!!! Thanks Krokus
ive been glassing straight UV for years I only use MEKP under lams and fins and tints, stuff where the uv doesnt work, and when i do use it, i mix a little batch, say for a lam just a capful put it on first and then use my regular un-mekpd’ on top of it. You can sand a hotcoat after 30 minutes tops no problem, heres my question, one of the primary benefits of UV resin is the ability to re-use it, If you put MEKP in it you ruin that trait, i catch all the resin i dont use and re-use it, drums go further… http://www.surfboardglassing.com
I don’t do enough boards right now to worry about the waste,…time management is more what I’m after. Forgot to ask earlier a VERY important question. I use halogen bulbs in my overheads and standard 8" flourescents in the light boxes. Do these give off enough UV’s to activate the catalyst? Krokus
only if its there for like 10 hours. Time management? Its still faster with the UV than the MEKP glass put in sun for no more than 30 seconds, back inside for like 5-10 minutes back in sun for 5 your done. and you can sand Mekp you still wait 20 minutes but should wait almost overnight to sand. I have a tube so it doesnt really mater to me it has a timer i set the board in and go. If Im really busy they go outside. http://www.surfboardglassing.com
I’m not sure I got an answer to the question. Are you saying there is enough UV light coming from the flourescents and halogens to activate the UV catalyst?? I DO NOT want to activate it with the lights, especially accidently. I like the flow of the resin and SA rise with MEKP, what I want is quick cure out so I can move on to the next step faster. It’s funny, there seems to be a UV catalyst movement goin’on as well as epoxy. I just want to blend the positive aspects of the two different catalysts. I also don’t want to be moving boards around any more than necessary. Bad things can happen if you get careless while moving unfinished boards! I can appreciate the total UV cure but I am not set up to facillitate moving boards easily. Now, How about the lights are they safe or should I mix up a batch and see if they set it off? Thanks for the imput, I am also assuming that the UV cure produces little if any additional heat? Is this correct. Krokus
if you left a UV board under flourescent lights it would take like 10 hours before it would even start to kick, My only point is why use extra cash on MEKP really theres no point in both its one or the other in my eyes. If your going to use MEKP and waste the resin why put UV in it? If your going to use UV why waste it by adding MEKP? By all means Im not trying to argue, I just see zero benefit in using both at the same time essentially its overkill, they both are hardners and really you dont need 2 hardners. I dont see that your gaining any benefits it seems to me just more wastefull. when I was an MEKP shop we would use a few gallons in a month, now im lucky to use a gallon in 6 months, http://www.surfboardglassing.com
I put a bit of the UV powder in my lamination (w/ MEKP) like you were asking about. So I laminate like normal then put it in the sun and its ready for the next step really fast. It works well. I agree with you - I want my lam to be kicked before I start moving it around. I guess Surflab is right that it is overkill to use two hardeners (if you have a UV chamber), but there is no set-in-stone way to laminate. We develop our own style for glassing as well as surfing. http://groups.msn.com/thegrasshoppersurfboard/shoebox.msnw
For laminating, you do not need MEKP mixed with UV cured resin. It will not cure faster, nor be any stronger. If you have decent daylight, a lay up on a board will be FULLY cured in mnutes. If the sun is not out it may take a few minutes longer. This is the fastest strongest way to laminate a board. Don’t even touch the MEKP. BUT, thre are a few drawbacks. If you are doing a dark tint, then do not use UV resin. remmeber, UV light needs to fully penetrate the layer(s) of cloth for a good bond between foam and glass. Very darkly tinted resin can prevent this. Hot coats with the UV resin are harder to do than the MEKP. I could go intto detail about that but i won’t. And for gods sake NEVER use UV resin put in a finbox without kicking it with MEKP. Also, you need to have a precise mix with the powdered UV catalyst to get the proper cure. I buy my resin premixed from Fiberglass Hawaii so i avoid the issue alltogether. UV resin will begin to cure the second ANY UV light hits it. So if you have a window where you are glassing, UV resin will bounce around and will begin to cure. But my experience is that I glass in a garage with 2 windows and a string of wondows on the garage door. To do a 10 foot board, it used to take a long time to do the lay-up, like over 30 minutes. at the end of that time the UV resin is begining to cure very slightly if at all. So don’t worry about that. Nor do you have to worry about overhead flourescents. Yeah, it will eventually begin to kick UV resin, but this will take hours maybe longer. But you should never leave a can of resin open nor in a clear plastic container. have fun Drew
I use mekp and uv cat. The reason’s for me doing this is I am in NE and I started doing this on color jobs because if I made a small batch for the lams it would be darker than the rest of the board around the lams.Surflab is right it can be overkill yet my lam room is small and I’ve been more productive this way.Now don’t use alot of mekp with uv it will have a yellow hue to it.I use 5-6 cc on each step.just enough to kick under lams and HC.
Also krokus just keep resin covered up and you will be fine. Windows are a bigger problem.
I’ve got windows everywhere in my garage, so I make a little room out of those cheapo blue plastic tarps, (on sale at Harbor Freight right now, $1.49 ea) I zip tie the tarps to schedule 40 PVC pipe, then I hang the pipes by hook from the garage rafters.You can even use shower curtain hooks. Once my lamination is done with the UV resin, I just take down the plastic tarps around the board. Presto UV kick. -Jay
I actually like some light coming in when I glass with UV. i have a wierd set up though that in the end benefits me greatly. The light comes in and rebounds off the floor and hits the underside of the rails first. This works well because with rails getting a short exposure they will be semi cured when taking her out in full daylight. Just seems to speed the process and at the same time makes the rails a tad less messy. Drew