Cruisers Forum

Join CruisersForum Today

Thread Tools Search this Thread Rate Thread Display Modes
Old 03-07-2011, 06:18   #1
Registered User

Join Date: Jan 2008
Posts: 277
Gelcoat applied, no catalyst used

Friend painted his anchor locker with gelcoat and did not add any catalyst. Has been "drying" for three weeks and is not hardened. He called Sabre, who shipped the gel coat with no catalyst, and was gven the option: remove with acetone and apply again. However, can a second batch mixed with the catalyst be applied directly over what's altready there and curing take place? To remove with acetone will be a very difficult job, but will the above solution work? ANY input will be greatly appreciated.

D.D. is offline   Reply With Quote
Old 03-07-2011, 06:27   #2
Registered User

Join Date: Jun 2010
Location: St. Petersburg, Florida
Boat: Gemini 3200
Posts: 718
Re: Gelcoat applied, no catalyst used

I've had success getting polyester resin to cure by mixing another batch with extra catalyst and topcoating the uncured resin. It's a bit tricky to get the topcoat applied before it becomes unworkable. Mix batches small enough that you can apply them in the limited pot life.


fgd3 is offline   Reply With Quote
Old 03-07-2011, 06:55   #3
Registered User
brankin's Avatar

Join Date: Jul 2010
Location: Florida
Boat: Endeavour 43
Posts: 232
Re: Gelcoat applied, no catalyst used

Your friend is probably out of luck having waited this long because the reactive monomer styrene has evaporated well below the level designed by the manufacturer to react and cure the gelcoat. Trying to put new gelcoat on over this layer will work but could lead to unintended consequences such as alligatoring.

The best bet is to wipe it all off and reapply a fresh coat and make sure it is the waxed version of gelcoat. Good luck.
brankin is offline   Reply With Quote
Old 03-07-2011, 07:20   #4
Registered User
sabray's Avatar

Join Date: Aug 2008
Location: Wash DC
Posts: 3,169
He could try a small spot with just pure polyester resin. Mix a very small batch and try it on a spot maybe 6x6"
sabray is offline   Reply With Quote
Old 03-07-2011, 09:59   #5
Resin Head
minaret's Avatar

Cruisers Forum Supporter

Join Date: Aug 2007
Location: Seattle WA
Boat: Nauticat
Posts: 7,205
Images: 52
Re: Gelcoat applied, no catalyst used

I used to run the gelcoat spray booth at a major production facility, and having done this before I can tell you there is no fix other than a 5 gallon bucket of acetone and a bundle of rags. Be very thorough and make sure all of the uncured gelcoat is removed, it will never cure and any gelcoat you put over it that does cure will almost certainly alligate. I've seen people go to great lengths to try to solve this, inlcuding spraying straight catalyst on the uncured gelcoat within an hour after it was sprayed. Nothing works, you're not gonna get catalyst down to the gelcoat that is actually touching the substrate, which is the part that matters. Worst case scenario, you overcoat it with catalyzed gelcoat, which cures nicely with no alligation. The uncured stuff will still be trapped under it, and eventually it will all let go, clogging your limber holes with gelcoat chips. Nope, there's no easy way out of that one. When you bust out the fiver of acetone, be careful of ignition sources, that much acetone fume is dangerous stuff! I'm still laughing at the guy in the yard who tried to provide ventilation for acetone fumes during a wipedown of his bilge with a shopvac. The shopvac was sitting under his open forehatch, and when it exploded the lid shot out of the hatch about fifty feet in the air! Even fans will provide ignition, be careful.
Oh, and make sure you use surface seal in the last coat for proper curing. If your buddy didn't know to catalyze gel, I'm guessing he's not familiar with waxing it either.
minaret is offline   Reply With Quote


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 18:18.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.