Will it EVER cure

Still working on my boatproject. While glassing in some reinforcements, lying under backseat in a hard to get at place, I ran out of poly. I reached out and grabbed container and made a new mix. Now 24 Hrs later the lay-up is like half cured, a little soft and very sticky ( usually sets in 1-2 hrs or so ). I even put a heater in boat yesterday, and tried to brush a little MEKP hardener on surface. Guess I must have been low on catalyst, when mixing, though I never experienced that, and I've used up 5-6 gallons now. Will it ever cure ? Is there any trich to do, maybe Hooty or any of you glassmanics can help mee ?

Re: Will it EVER cure

I missed talking to Hooty the last 2 nites myself.<br /><br />I worry that maybe he's been arrested again.<br /><br />Its so bad when he gets caught in those roundups during a barfight. <br /><br />When they run him across the computer, it always kicks back this nonsense about his 8 or 9(that we know of) ex(crack *****) wives wanting money for all them kids, jumping bail, license numbers recorded at armed robberies tracking back to him,,,, failing to appear for DWI court cases,,, aiding and abetting escaped felons,, the list goes on and on. I hate it when he is cuffed, in the back of a squad car, and has to listen to all that over the Police radio.<br /><br />Anyway;<br />I'll check with him about your question, if he's allowed visitors down at the jail, when I go down there tomorrow night to visit some other members of his gang, I'll ask and report back. <br /><br /><br />In the meantime, let as much Sun shine on your project as possible. I've mixed 'glass (after dark)that normally kicks off in 10 minutes. It stayed sticky for 10-12 hours-- until the Sun came up and it's radiation hit it. <br /><br />Then, in 20 minutes, the stuff kicked off, and hardened up tougher than Chinese Algebra. I've found that electric lights aren't nothing compared to the Sun for curing 'glass & epoxys. <br /><br /><br />Anyway:<br /><br />If we don't hear from Hooty before then, <br />he's supposed to break out of jail and go with me Monday when we grab a$$around with different props and the new stator on "POCO LOCO", to see if we can get it over 70mph under 6000rpm. <br /><br />Unless we get really drunk, and forget,,, I'll tell him to look ya up here, and pass on his wisdom of chemistry.<br /><br />But, be careful. <br />I've hung with him over 20 years on a daily basis, and after him getting me so confused about fiberglass/epoxy stuff---- I switched over to Aluminum boats.<br /><br />Ed.

Re: Will it EVER cure

Oops! I'm not sure if undercatalyzing will prevent it from curing, I don't think I've ever done that, but polyester is not like epoxy in that respect as far as I know so it should cure eventually. I don't think brushing on hardener will help, resin doesn't work like that and all you'll do is cure the surface....maybe.<br />I'd leave it another 24 hours and see what it's like, if it's harder then than it is now chances are it will cure in time.

Re: Will it EVER cure

Thanks - petrolhead and Ed <br /><br />I finished the job this morning and guess what - the rest of it wont cure either !! This time I know I added the right amount of hardener. Both jobs were from a new gallon of resin, opened right now. Can resin be bad ?? I bought it 2 weeks ago. It starts to cure in pot, gets thicker and kind of "thready", and then the process aparently stops again. I covered the boat and left heat on all day, but brush in pot was still useable and soft. So was the one from yesterday, in garbage bag, just a little stiffer. How comes ?

Re: Will it EVER cure

The "right" amount of hardener is the amount it takes to kick the resin within a few minutes or hours. The amount is totally dependent on weather conditions. I'm guessing part of your problem is from low temp and/or high humidity. Both GREATLY inhibit kick times...especially humidity. From now on, take readings on temp and humidity and note how long it takes to kick. Log times and adjust hardener to suit conditions. This is how pro glassers do it to take the guesswork out.<br /><br />Polyester resin will eventually kick dry with minimal hardener. But may not reach the max Barcole hardeness if it takes too long on the initial kick time. Polyester continues to cure after it feels hard and dry. Resin mfgs used to tell me the resin needed to kick dry within a few hours and then it took another 14-30 days to fully harden.<br /><br />Hot batches of resin are better to help kick off slow cures because they are more predictable than straight hardener. They seem to work better than a heat gun...but neither will work well after a long time has passed. Mix 5-10cc per pint (or what kicks in 5 minutes in your clime) and apply quickly. In 85F temps and 90% humidity I use 5cc to kick a slow glass job. In comparison, 40cc would be used to build a sanding surface.

Re: Will it EVER cure

I had a section that was slow to cure, took a week if I remember rightly. It did cure though, and all was well. I was doing my work in wildly erratic temp conditions at the time, so it was no great surprise. Good luck...

Re: Will it EVER cure

Sounds like you are using laminating resin which remains tacky, you can recoat with finishing resin.

Re: Will it EVER cure

Its nut just tacky, the brush is still soft and useable after 12 Hrs !! The laminate is firmer though. Can anything be wrong with the poly ?? I hadnt had others acting like this. It was 20 deg celsious today and sunny. The area can not be exposed to direct sun.

Re: Will it EVER cure

This sounds very odd, what percentage of hardener are you using?<br />Just one further thought, is this the same brand of resin as you used previously, and did you buy hardener with it or is it stuff you already had?<br />When I first started using polyester resin over 25 years ago it used to come in 3 parts, resin, catalyst, and hardener. You had to add catalyst to the resin first, then the hardener to make it cure, I think the idea was that un-catalyzed resin had a longer shelf life. I haven't seen it for many years and I'm pretty sure all resin is now pre-catalyzed, it's just a thought though...

Re: Will it EVER cure

I bought the resin from the same boatbuilder. <br />It is in neutral containers. The previous resin he sold me was a little greenblue coloured, this was a little milky, non coloured. Hardener came with it. I used 2% as I always did. Usually I get a 1 gallon jug, this was in 1/4's. I noticed there was a thin layer of thickened resin under the lids, does this mean its of an old batch ?? Everything of this hardly cures, I will call him tomorrow.

Re: Will it EVER cure

I didnt put it right, it is premixed with catalyst, it only needs hardener.

Re: Will it EVER cure

I don't like the sound of that thickened resin under the lids, it may well be an old batch. Normally when it gets old the whole lot starts to get thick and syrupy, but it's still useable for some time after that, at least the resin I use is, different brands may have different properties as they age.

Re: Will it EVER cure

You asked "Can resin be bad?" - Yep it can but don't have a clue where to go from there.

Re: Will it EVER cure

I wonder if you got epoxy resin and are trying to cure with MEK. You need hardner in a 2:1 0r 3:1 ratio depending on the resin.

Re: Will it EVER cure

I think he'd notice the price difference if it was epoxy, and probably the smell (or relative lack of it) too, and I don't think it would have cured at all with polyester hardener.

Re: Will it EVER cure

Called the boatbuilder this morning. He says it is probably because of extreme high humidity. Thats the reason the resin was kind of milky white. He had another costumer complaining over exactly same batch. I did 4 stringers under the back seat of my boat. Its a double shell boat and I crept down thru a hole in seat and lay on my side working. Certainly do not want the job removing mat and resin, and doing it all over again, although he offered to replace all for free !!! It smelled as usual, still does.

Re: Will it EVER cure

I back from work - and lo and behold - it is cured lets say 95 % now, where the heat blower hits it it isnt even tachy, gues it's be fine, just needed more time.

Re: Will it EVER cure

If I recal right, poly cures by abcence of air. If you cover over the resin with wax paper and press it down to "seal out" as much ambient air as possible it should speed the eventual cure.

Re: Will it EVER cure

It cured in 4 days - op to only 5-6 slightly tachy spots, which are gone now after 5-6 days. Guess it was the humidity, although I never thought it would interfeer that much.<br /><br />As the construction I made has plenty of strength, I decided to just leave it.<br /><br />Thanks for all your replies.