Gelcoat OOPS ! ! ! Forgot the MEKP catalyst

[home made tunnel]

I may or may not have forgotten to add the MEKP catalyst to one shoot while putting gelcoat on my boat...

The 1st thick layer was fine - 3 x 750mL reloads of the spray gun did the whole boat bottom.

The start of the 2nd layer (about 30 mins after the 1st was applied) is where I forgot the MEKP. I emptied the 1st 750mL's and said OOOOooo $h1T!!!! Thinking how I can save it - - - I quickly mixed up another batch with about 4-5% MEKP catalyst, and resprayed that entire area.

WHO KNOWS if this is going to save it or not - - - I may have to wait a couple weeks to find out.


I then went over the rest of the boat, then finally one last time, another heavy coat with the wax additive to seal it all up.


DO Y'ALL THINK I'M IN TROUBLE ?!?!?!

[Gorilla0178]

Fingers crossed, I would have stopped and let what you did kick off cure, then scrape and wipe the uncured gel off and started again. Gel is thick and putting catalyzed gel on top of uncatalyzed gel without it mixing, might not kick off. At worse you'll have to peel the kicked off gel from the uncured gel and redo that area.

[XstreamVking]

Got mek under it, and mek over it, it will prob get hard. You would be surprised what you can get away with doing gell. Only talking about 20 mils of thickness. Get it warmed up and cure it for a week, start sanding and you will know.

[Murph]

You should be ok and you did the right fix.
Polyester gel is like a setup of Domino's.
To start them falling we add a little hardener.
The more hardener we add the more points our Domino's will start falling from, the faster they fall.
If they stop, then a new setup of Domino's tying into the old will get the old setup falling again.
Epoxy on the other hand is a setup of Domino's laying flat, they can't fall over.
You stack the proportion on top of each other, say 1 hardener and 3 resin.................
Then you have to mix all the Domino's up and heat will fuse them together.
Add more or the wrong proportions will just mess them all up without the proper fusion.
With a proper fall (Polyester) or mix (Epoxy) you win the game.

[home made tunnel]

Let my lapse of thought processes be a lesson to all- yes it worked! As long as you have enough MEK in the under lying, and over lying layers, the gel will harden. I sanded it a bit and it looks great. I can't even put a mark in it with a coin or my fingernail.

[Gorilla0178]

Awesome, glad it turned out ok.

[XstreamVking]

You got lucky. The dominoes fell just as described by murph.

[home made tunnel]

The dominoes fell perfectly -

[GregAdams]

Happy you got away with that one Your other thread went quiet. Looks like you went no wax except for the final coat?

[home made tunnel]

Happy you got away with that one Your other thread went quiet. Looks like you went no wax except for the final coat?

Bingo - couple layers of no wax - then final layer with wax. Worked perfect. About an hour of set time inbetween coats. (except for the one batch I forgot the MEK, I immediately went back over that).
The final layer will be with the duratec additive after I sand this orange peel down smooth. The stuff sprays like truck bed liner -

The other thread I'm keeping for the regular progress updates. That'll be the full start to finish thread lol. I deviate when I need technical advice like this.

I thinned the gelcoat about 8% with styrene thinner, and used a spray gun from harbor freight with a 2mm tip.
http://www.harborfreight.com/33-oz-l...gun-61455.html

[XstreamVking]

SHHHH! Truck bed liner is a secret speed coating.....

[GregAdams]

SHHHH! Truck bed liner is a secret speed coating.....

I used it in the back of my truck and it didn't go any faster...

[XstreamVking]

Try it going backwards, big difference.

[GregAdams]

I never thought of that ... lol

[bullet20vee]

Good job man. I don't envy you at all at this point, I did all of my wet sanding, buffing and polishing last year at this time. The prep work and spraying is the east part.