Thinning Parker Gel Coat

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Ranger Tim

Well-known member
Feb 18, 2006
Reaction score
Central Virginia
Eminent Parker Scholars,

I am currently doing restorative work on a Scout 172 and I am ready to apply gelcoat to some hole repairs. What is a suitable thinning agent and mix ratio for Parker factory gel coat, applied with a Preval air pump sprayer? The Parker gel coat is a fairly close color match and I have a generous quantity of it on hand.
I have done this.
Mix gelcaot with clear , add hardener, & thin out with acetone so it will spray in a spray gun.
I'll have to check with someone who knows the name of the clear that I used, I can't remember the name right now as it was 3 years ago .
I tried it earlier today thinned with acetone and it worked well, just wondered if it will harden properly. I wil check the test strip tomorrow. I used twice as much hardener because of the colder temps in the shop. I will post the results here.

Did you mix wax IN with the gelcoat or did you cover with wax or mold release after spraying?
I am spraying the final surface coats over some hole repairs in the top deck. Some idiot drilled one inch holes into the bow deck on this Scout to mount a trolling motor using garden variety zinc moly bolts. The holes were hogged out with a 1/2 inch drill bit and were very ragged/nasty. Unfortunately the holes are located in a section of non skid pattern that I cannot duplicate without making a mold -- and I'm not going to all that trouble. Smooth will have to do. The boat owner is happy just to have the holes filled and I'm doing it for free. I love tinkering but I hate gel coat.

The pictures got posted in reverse order, BTW. :?:


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Have you heard of Gibco Flex Mold?


Thanks Dale!

I have been wondering if there was a shortcut around making my own pattern mold. I will check it out.

The repair will have to be refinished next winter. The owner wants the boat to fish for the croakers and trout by this weekend. So it's gel coat smooth and forget it for the season. At least she won't be taking water through the 30+ holes somebody drilled everywhere. The previous owner had a bunch of cheap Cabela's add ons everywhere; anchor winches for mushroom type anchors, goofy plastic rod holders, plastic rod racks, tackle storage bins, etc. Holes everywhere! All that stuff was fastened with zinc screws, half of which were broken off in the fiberglass. Several holes in the transom, and none of the add ons were suitable for salt water. Lots of drilling out broken and rusted screws.

Why do people do that to their boats?

Re:parker GelCoat wax, I believe I was told by the good folks at 3A Marine in Hingham that the exterior parker factory gelcoat I bought HAD wax while the interior version did NOT have wax. I'll check my notes on the boat in the am to be sure.

Cost was $30/qt. They had the factory ship some up inside a new delivery in order to avoid the high cost of shipping small amounts of HazMat's.
Regarding wax and Parker gel coat cure: I did a test patch on a flat table with no covering and the gel coat was tacky in four hours (55 degrees) and was hard and not sticky in 48 hours. I have not done the gel coat treatment to my repair yet, but will after I evaluate the test patch tomorrow. I will either use plastic covering or nothing at all, depending on the test patch result.

The Parker gel coat sample I have tends to have a darker color fluid barely visible on the surface prior to mixing. Is this a wax? I am learning valuable lessons now before I attempt to fabricate my own bulkhead helm station. I am not keen on cutting a factory helm in half, especially at $300 cost. Besides, I can make it with cool compartments and other neat stuff! I like playing with West System epoxies, it's the gel coat that is a nasty business.
Ranger Tim":2jjm8i4p said:
I like playing with West System epoxies...
Switch to Raka epoxy, , and save 1/2 to 1/3rd off the price of West Systems. Plus, it's an easier mix, just a 1 part hardener to 2 parts resin. Simple ... and no noxious odors either.
Too late! I'm already set up with the West System stuff. The mini pumps are no-brainer easy and I have little brain left, so this is a boon. When I need to update my supply of resin and hardener I will definitely look up the Raka Epoxies. Thanks for the tip!
Ranger Tim":1k5bqr77 said:
The owner wants the boat to fish for the croakers and trout by this weekend.

Where the he!! are you finding croaker and trout this time of year?
Water temp at TPL is 44 degrees!

BTW - when you are ready to duplicate that non-skid, PM GW204. He did the same thing on his old 204 Grady and it came out great!
He posted step-by-step project photos to ClassicMako...
Croakers are swarming the inlets at Rudee and Lynnhaven, have made their way up the James to the M&M. Reports of them in the mouth of the York and at the CBBT.

I meant to say flounder, not trout! Striper are still being caught off Cape Henry in 30+ lb. sizes. Crazy year, Huh?
Crazy indeed!

I caught exactly one croaker in my home waters last year. They just never showed up. :cry:
Hopefully this year will be different. :)
Megabyte":1yycw5pe said:
Crazy indeed!

I caught exactly one croaker in my home waters last year. They just never showed up. :cry:
Hopefully this year will be different. :)

Kevin, I had to travel all the way south to the Diamonds (So. of Sharps Is. Light) to find croaker last year. I've moved to Solomon's so my croaker fishing should get better this year.