it was my first time using resin research last night. i used a scale to measure it out. i read somewere on here that to get the resin a little runnyer to put it in hot water for a bit . i did that and it worked really good . i then mixed the hardener and additive f in with the resin. but i then put the mix back in the water while i mixed it.( i think that was my mistake ) because i poured some on the board and started spreading it around went to grab the mixed resin a pour some more on the board and it was super hot and smoking and almost rock hard. but the resin i had all ready poured on the board was fine . i was able to finish the lam coat and it dryed fine when i checked it this morning. but why did the resin in the bucket cure so fast?
resin cures faster when it is a large quantity. When you mix it, get the majority out of the bucket.
It was smoking because of exotherm. It is the release of energy from the chemical reaction between part A and B. You did nothing wrong, it would happen to anyone. Just don’t let a lot of it sitting in the bucket…
EPoxy resin reaction is an exothermic reaction(meaning it creates heat during reaction). It also cures faster when warmer, this is a positive feedback system, each feeding the other.
Warming the resin up before mixing is fine, do NOT warm it further after mixed and get it out of the pot as soon as you can so the positive feedback of the heat reactions/effects doesn’t get out of control.
I made the exact same mistake you did. Don’t provoke the beast! A little warming is OK, but push it too far and you release the beast.
If you smoked your epoxy, it’s damaged. It may have cured, but it’ll never be as strong as it should be.
okay thanks alot. ill remember that. i now its been said on here a million times before but epoxy is awsome to work with . no mask rules!
Do this instead – heat resin and hardener separately, or just heat the resin and nevermind the hardener. Then mix together with additive F briskly, and pour it out right away.
Put any remaining resin that’s in the bucket outside in the snowbank until you’re ready for it (oh wait, only Great Lakers can do that … )
don’t heat the hardener at all.
the point of heating is to make it flow better. the hardener isn’t nearly as viscous as the resin, and heating offers no benefit.
one better…
Warm the resin only if it’s cold and really thick. It should be no thicker than corn syrup (I love the food analogies). Don’t warm the hardener by itself, ever. Warm the resin until it dosen’t feel cold in the bucket. But it should not feel warm. Room temp is perfect.
Or, here’s my trick… if you like to paint the rails before pouring it out on the flats, don’t warm the resin at all. Just mix it with the hardener when it’s thick and cool. That way it goes on heavy and you have plenty of resin for the lap. Once the rails are painted, then warm the mixed resin and hardener for a few seconds in the microwave and pour it right out. That way it goes on thin on the flats and easily penetrates the cloth.
I had hard times mixing the resin and hardener adequately under 55F ambient temps. When I started taking hot tap water and making a water bath in a 5 gallon bucket, and leaving the resin in the bucket, the mixing problems ended. As noted, it is a problem with the resin viscosity, so heating the hardener doesn’t help it to mix better (but will accelerate the initial cure).
Yeah, the resin is an exotherm, once it starts curing it will heat up depending on the surface area to volume ratio. In other words, mix and pour it out, don’t leave it in the bucket.
or use a slow resin
you cant slop epoxy around with squeegee like poly
it foams up and basically excessive waste to save a few minutes time
if you dont want to use a squeegee to prevent bubliing
this is the deal
lay out and cut your cloth
roll it back halfway
mix resin in a bucket stir for 100 seconds
and pour into a tray
use a 4 inch brush and paint half the the board inc laps (takes about 2 minutes)
roll out the cloth back out over the resin and stretch it to the rail
the reisn will soak through the cloth in a minute or two
roll back the other side and do the same
paint down the laps with remaining resin
and hit any dry spots with the brush
whole process takes 15 minutes
shortboard 300 grams is plenty
dont piss around with heating it
unless its really cold and you can warm it up in about 30 seconds with a hairdryer when its in the tray
i dont need a tray cuz i use slow systems
water is not a good idea
If you don’t warm the hardener it will cool the resin back down again when added. Mix the resin and hardener together and then warm.
I’ve been heating the mix forever… works fine for me, too.
Also… the hair dryer trick works. I’ve held 700mL of cold, thick resin over a space heater while I stirred it with a paint stick and had it thin out in less than a minute.
ya i deffinnetly was using it the way i would with poly. i mixed about 600 mils for a 6’10" with one layer of 6 oz.cloth iam thinking ill just mix about half of that for the top lam. and brush on instead of squeggee .then if i run out ill just mix some more.and i wont stop stirring it. it is a little cold here and i like the consistancy that the warm water bath got the resin. but i deffinetly wont warm the hardener too here is a pic of the board so far. my buddy wanted the board black on the bottom with a white top so we sprayed the bottom with black gesso acrilic paint. the paint sprayed under the tape a bit but ill cover that with a blackpin line under the gloss coat. its my first board hot wired from a block of eps foam 
thanks again for your help
6 10 you need 350
but i could do it with less but the laps use a lot
if you zipper the laps
then 250 would do it
i did one the other day that worked good
i taped of the deck and mixed 100 and painted the rails and deckside laps
flipped the board and rolled out my already cut cloth halfway
mixed 250 then used a brush as i described too paint the foam(or wood)
roll the cloth out over that and then roll back up the other end that isnt wet
do the same thing
when you go to brush the laps down the resin is already there
i basically hit it with squeege just to get out some bubbles and excess if any
drag from middle out to rails
i can do the whole process with almost zero waste and no or very little drips on the floor
laps are brushed from middle to ends
use a hairdryer in the tray
its quick safe and easy
you dont need the resin hot
just so it flows out with the brush
if its warm and or the blank is sealed
1 to 1 ratios are not hard to achieve
although youstill have to fill coat it anywy
Epoxy is certainly a different beast from poly. I remember Greg Loehr posting about the polyester mentality. Dont’ try and work it into the cloth as you’ll make it froth. Just spread it. I’ve gone back to the thalco squeegees as well as I’m finding the plastic ones just too unforgiving.
never had this problem…always heat the resin (not hardener) in the micro for 15 secs or so…didn’t i hear someone blew up their kitchen trying to heat hardener? the water bath works too…and no explosions! definitely get the goo out of the bucket asap, as others have said, to avoid the exotherm…
If you don’t warm the hardener it will cool the resin back down again when added. Mix the resin and hardener together and then warm.
its called a tray
no buckets in epoxy
and water and micowaves are a pretty pointless
for me personally i wouldnt use a resin that need heating anyway
if you have a room at 20 degres c you shouldnt need to heat the resin
soonycheeba take my advice its good advice
shown to me by a guy that heads teams that build superyachts
im going to delete the post soon
i hope you got it
iam gonna try that for sure i like the fact that by painting the rails first the laps have something to stick to and hold in place . with out having to force it through the cloth. thanks again