It is currently August 18th, 2019, 4:23 pm

All times are UTC - 5 hours




Post new topic Reply to topic  [ 5 posts ] 
Author Message
PostPosted: November 24th, 2017, 4:01 pm 
Offline

Joined: June 28th, 2001, 7:00 pm
Posts: 1650
Location: Freeland, Maryland USA
(Cross posted on another board, I really need some quick advice & opinions from folks with gel coat experience)

Um, asking for a friend and all that. I am a gel coat virgin, saving myself for the right boat.

We have again repaired the worn down through the gel coat and into the kevlar cloth stems on a couple of boats that see hard limestone, oyster bar, wormrock and beach landing and sandy drag ashore use in the Everglades.

Last fall we experimentally tried using S glass, E glass and Dynel in different wear areas, installed with a mixture of G/flex and West 105, peel ply on top on a couple boats.

The installation was well accomplished. However, neither S or E glass lasted a season, while the Dynel is still going unscratched strong.

Back at it again. All Dynel cloth this time. We sanded and cleaned those previously repaired boat stems, and laid the same resin mix atop long, thin, precisely cut strips of Dynel on the stems. Both boats look great so far, the Dynel flush and compressed under the peel ply without bulging epoxy soaked rough like an old sweatshirt. Sweet.

I beveled the tip ends of the cloth after it cured, and needed to use a file to make any progress. Dynel is tough freaking stuff. Stem tips file beveled smooth and re epoxied. It looks niceeeee. So far so good.

What also wore off, starting on the first trip last fall, was the enamel spray paint we applied over the resin last fall for UV protection. Those boats are worked constantly in a harsh environment for 5 months, and then spend much of the rest of the year outside on a trailer. Some UV topcoat is called for.

We, shop partner Joel and I, have been back and forth about what to use as a more durable than spray paint UV protectant top coat.

One part and two part poly and epoxy boat paints are pricey, and in Everglades conditions I doubt even their longevity as a UV top coat. Nix that idea until at least next fall when the boats come back for their annual tune up. I never shoulda mentioned that lifetime warranty nonsense, and probably should do that warranty work in the spring after hardest use.

Our shop debate regarding top coating those now lovely flush and near seamless deep vee Dynel stem protectors:

I want to simply brush on, not micron thin spray on, a coat or two of ubiquitously available Rustoleum enamel paint, which I already have in the shop in the needed colors. And do that every year in paint worn areas. Four bucks a can.

My shop partner, whose boats they are, bought a can of ClearCote white with wax gel coat and has unperturbed visions of rolling gel coat atop the epoxy and Dynel as a thicker sacrificial layer. And I have done my best to perturb him.

Trying mightily as I can to conceal my bias, I am horrified at the gel coat idea, and will not list all of my concerns, but, eh I believe it will look like stucco without days of sanding fairing and recoating. That it will, at best, spider crack or chunk off at any impact. That it will be a massive PITA to sand back down to epoxied fabric if it fails. That it may not adhere well to cured and amine blush removed epoxy resin (researched opinions vary)

None the less, I kinda want to see him try it. I did have him sign a notarized agreement to hold me gel coat blameless, so whadda I have to lose?

What say yee who have worked with gel coat?


Top
 Profile  
 
PostPosted: November 27th, 2017, 12:07 pm 
Offline

Joined: March 23rd, 2006, 11:21 pm
Posts: 1076
Location: Burns Lake, BC
Back off and let him learn his own lesson.

Who wants gelcoat anyway?
It's like hairspray... it's no good for anyone but the owner. But man they look good.

My touchup paint is an oil based enamel.
Sure it scratches off but goes on just as easy and like you said... cheap.

Show us some pictures later so everyone can learn from this. :D


Top
 Profile  
 
PostPosted: November 27th, 2017, 1:14 pm 
Offline
User avatar

Joined: August 11th, 2002, 7:00 pm
Posts: 5505
Location: Sunny Wasaga Beach
Canoeheadted wrote:

Who wants gelcoat anyway?
It's like hairspray... it's no good for anyone but the owner. But man they look good.

My touchup paint is an oil based enamel.
Sure it scratches off but goes on just as easy and like you said... cheap.
s. :D



I was considering doing gelcoat a few yrs back so I posed the question on here. I was advised by John Winters, no less, not to bother with gelcoat but to use paint instead. Seemed to work just fine!

_________________

Old canoeists never die---they just smell that way.



Top
 Profile  
 
PostPosted: December 3rd, 2017, 12:45 pm 
Offline

Joined: June 28th, 2001, 7:00 pm
Posts: 1650
Location: Freeland, Maryland USA
(Since I cross-posted the gel coat question here I will cross-post the results)

Gel coat over epoxy resin 24 hour cure results

Yesterday we top coated the newly installed Dynel cloth and epoxy resin mix. The epoxy had peel ply laid overtop when applied, and with the peel ply removed the resin dried for almost a week until sandably cured.

I guarantee there was no amine blush remaining. We used a blush removing peel ply layer, and once cured the resin was scrubbed with soapy water and a new ScotchBrite pad, clean water rinsed and alcohol wiped. We even cleaned, rinsed and dried the resin area a second time a few hours before top coating.

The long narrow Dynel run strips on the stems were UV top coated using Rustoluem white enamel paint and were dry to the touch in 5 or 6 hours and fully dry the next morning. Any amine blush would have screwed that up. Been there.

The experimental gel coat brushed thinly atop the small center patch was still tacky in linear streaky smears this morning, despite keeping the shop at 72F for a full day.

FWIW, the gel coat was the type with wax already added, which from the literature does not need a barrier layer or additional wax additive. Or so we thought.

The gel coat was well mixed in proper catalyst proportion.

The shop is still at 72F and I have the boat back right side up with a radiant oil heater directly under the still tacky gel coat. I do not have high hopes, but if it never cures it will soon be removed by oyster bars and limestone.

I have no clue what went wrong. I know what we did right.
Fresh, unopened can of gel coat bought a couple weeks ago
Carefully measured and properly mixed.
New, clean unused mixing cup and fresh clean brush. We only made 2 ounces of gel coat in a graduated cup.
Not amine blush
Not uncured epoxy. The repairs made epoxy resin dust when sanded
No too cold. Min max shop thermometer shows a brief low of 68 when we had to open big shop door to bring a 20 footer inside, otherwise a steady 72 F for a full day and counting.
Not too humid, the highest shop hygrometer got was 57 percent.

Uneducated guesses
Maybe using the type of gel coat that requires a barrier layer or additional wax additive would have been preferable.
Maybe this can of gel coat sat on the vendors shelf for a year. Doubtful with ubiquitous white gel coat from Jamestown Distributors.
There were a couple of small cracks and divots in that boats gel coat which had received no resin. We dabbed some gel coat filler in those cracks. Most of those gel coat over gel coat repairs finally set up. A few still have not. WTF?
Maybe, just maybe, gel coat over epoxy resin is simply a bad idea no matter how well cured and cleaned.

Any more educated guesses?

Any idea what to do with the 14 ounces of gel coat remaining? If it is still tacky tomorrow I could mix up another batch with a few additional drops of catalyst and recoat it.


Top
 Profile  
 
PostPosted: December 4th, 2017, 4:20 pm 
Offline

Joined: June 28th, 2001, 7:00 pm
Posts: 1650
Location: Freeland, Maryland USA
Gel coat after 48 hours in a warm shop and gentle direct head. Still tacky.

Screw it, I need to shop space, and do not need to continue keeping the shop that toasty warm. If it has not set up yet I doubt it ever will, that boat goes outside to make space.

Should I try to remove the still tacky gel coat? Acetone maybe? It is gonna rain and I do not want it to ooze white gel coat down onto the red part of the hull.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 5 posts ] 

All times are UTC - 5 hours


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group