Moderated Discussion Areas
  ContinuousWave: Whaler Repairs/Mods
  Spraying Gel Coat?

Post New Topic  Post Reply
search | FAQ | profile | register | author help

Author Topic:   Spraying Gel Coat?
Sinclair7 posted 04-05-2002 01:24 AM ET (US)   Profile for Sinclair7   Send Email to Sinclair7  
Does anyone have any experience spraying gel coat? I have seen small, disposable spray cans that are used for touch up paint work. Thay have a small glass container on the bottom for the paint. I was wondering if I could use this to spray gel coat. What should I use to thin the gel coat so it can be sprayed?
jimh posted 04-05-2002 08:52 AM ET (US)     Profile for jimh  Send Email to jimh     

sargerator posted 04-06-2002 03:33 PM ET (US)     Profile for sargerator  Send Email to sargerator     
Just refinished transom on my Montauk. Wood dowels in old attachment holes and two coats of epoxy. I bought the Preval sprayer that you mentioned. I thinned the gel coat with 20% by volume acetone and began to spray. The sprayer became clogged and I ended up using a brush to finish. I found that the gel coat was to thick even with the max 20% acetone thinning. The airborn gel coat was noxious and burned my skin. Suggestion; if you don't have the proper equipment, ie, full body suit with face mask and air filter, just use a brush. The gel coat goes on pretty good with the brush.
Happy Sailing
Bugsy Malone posted 04-06-2002 03:50 PM ET (US)     Profile for Bugsy Malone  Send Email to Bugsy Malone     
Yeah using Strawberry or Lime sure makes a difference in how yeah go to it!

bang bang

pamlico posted 04-06-2002 10:36 PM ET (US)     Profile for pamlico  Send Email to pamlico     
As far as spaying it no,...but if you attempt to roll it on make sure you use a quality roller. Dont attempt to use those cheap ones you can find in Wal-Mart that are marked 3 for a buck. The cheap ones shead there hairs, so if you need to cover a large area and a sprayer is not available or you dont have much expeirance in using a sprayer when it comes to gel-cote get the more expensive rollers. There usally around $2.50 or 3 bucks for one. If you have a large area to cover you might want to by a couple of them because if you add plenty of hardner your sure to get clumps in the paint, especialy if the paint is sitting, in other words TIME IS MONEY. And clumps can drive you INSANE!! As soon as you see a small speck or blob on your finishing discard that roller and grab another. If your doing touch ups I would surely go two coats. If your going white over another color such as battleship gray it will take three. I did a 22 footer that was battleship gray and with no expeirence with a sprayer I was forced to roll myself silly. The first coat had the impression of orange peels, second really blended well at that point. I sanded to a smooth finish with some high grit paper. And the final coat came out wonderful. I made many mistakes in the process and learned from everyone because gel-coat is $45.00 a gallon. And as for brushing gel-coat it is fine as well for those small nicks and little obscure areas. Hopefully this will help someone.

Sinclair7 posted 04-07-2002 03:55 AM ET (US)     Profile for Sinclair7  Send Email to Sinclair7     
did you thin the gelcoat when you brushed it on? Pamilco, did you also thin the gelcoat? Thanks for the responses.
Sinclair7 posted 04-07-2002 03:55 AM ET (US)     Profile for Sinclair7  Send Email to Sinclair7     
did you thin the gelcoat when you brushed it on? Pamilco, did you also thin the gelcoat? Thanks for the responses.
pamlico posted 04-07-2002 04:31 PM ET (US)     Profile for pamlico  Send Email to pamlico     
No I didn't thin it. I'm not very familar with the process of thining gel-cote. And with the project that I had in covering up another color I really didn't want to thin the paint. There is several different types of roller sizes that offer good quality rollers that don't loose there hairs fibers. Those different sizes are great in working in small and hard to reach areas. And when using a brush, please get a quality brush. Ive used a brush in areas such as hard to reach areas such as the areas around the console and nothing is worse than those bristle's breaking loose and ending up in your work. And for some added info I do beleive its INTERLUX that now has developed a gel-cote that is ultra-violet protected and is scuff proff from those individuals who like to board a boat with out the proper foot wear. I would check your local marine supplier for this item but im sure its a whole lot more than a straight base white gel-cote. Take care and happy cruising.
pamlico posted 04-07-2002 06:59 PM ET (US)     Profile for pamlico  Send Email to pamlico     
One more thing,... Im going to school part time as a marine engine technician,..I just called my instructor and asked him did he know anything on spraying gel-cote. He said" Yes, I tried it once and it clogged up the end of my jet at the end of the sprayer, plus the air pushing through the sprayer was'nt freindly at all it began to clump on me faster than normal and before it was over I was out $10.00 bucks". So just a minute ago I called my wifes Uncle he is a boat builder for Hatteras Yachts and he said Hatteras uses a process where they buy the gel-cote in 55gal. drums and use a vaccum pump to pull the gel-cote from the drum and the operator keeps a eye on his work and the flow of the gel-cote as it hits the hull. Any slight disformaty and the process is stopped and the end of the sprayer is cleaned. The vaccum pump only draws the gel cote from the drum and does not allow air to enter the drum and then in another process air is pushed to allow the gel cote to leave the hose. He said its very complicated process and only a certain few do this job for Hatteras. And the main thing he said was not to allow air into the drum and we all know what air does to paint, DRIES! I hope any of my info is helpful. Happy cruising!
sargerator posted 04-08-2002 11:04 AM ET (US)     Profile for sargerator  Send Email to sargerator     
Yes , I did use the rest of the thinned gel coat. It wasn't clumping so I figured it would still be good. Spectrum says you can use up to 20% by volume of acetone to spray it on. I used the brush because I had them available for touch up along the keel, didn't think I would be doing the transom with a brush. Wish I had a roller!!! Also use only natural bristle brushes, the resin will melt the cheaper plastic bristle brushes.
tabasco posted 04-08-2002 11:22 AM ET (US)     Profile for tabasco  Send Email to tabasco     
Suggestion -

Home depot rents an airless sprayer. Has anyone tried this approach.

crosley95 posted 04-08-2002 04:50 PM ET (US)     Profile for crosley95  Send Email to crosley95     

just finished spraying the non-skid on a 67 sakonnet. purchased the gel-coat from spectrum. made a couple of calls to customer support on the process. thinned the gelcoat by 15%, added the correct amount of hardener and catalyst.... set the standard compressor to about 45-50psi.... sprayed using a standard series spraygun. went on like a charm. no issues whatsoever. this has been pretty well covered in earlier posts.


crosley95 posted 04-08-2002 04:51 PM ET (US)     Profile for crosley95  Send Email to crosley95     
standard Sears spraygun. sorry
Sinclair7 posted 04-09-2002 12:13 AM ET (US)     Profile for Sinclair7  Send Email to Sinclair7     
Thanks for all the replies. Crosely, did you thin with acetone?
flaglerdave posted 04-18-2002 04:42 PM ET (US)     Profile for flaglerdave  Send Email to flaglerdave     
when thinning gel , Acetone is not the best.
It will disturb the chemistry of gel coats
and can cause curing issues,( tacky )
There are thinners such as patch-aid or Speed patch made to assist with spraying gel coat. tThis is what is commonly used by Sea Ray factories from where I work.There is also gel coat spray can method aval. from a company in Central Florida "
I buy stuff from them . Good results !
DJS posted 04-20-2002 10:14 AM ET (US)     Profile for DJS  Send Email to DJS     
One thing that needs to be clarified in the use of conventional spray guns, not airless, is that there are two types of air nozzles. There is an internal mix and an external mix nozzle. Any material that is fairly fast drying will not do well with the internal mix nozzles. A lot of the low priced sprayguns come with the internal mix type nozzles. Also, you should be sure that the compressor used will provide a sufficient volume of air for the nozzle being used. Example: A compressor that is rated at 7.5 cu. ft. of air per second cannot possibly provide enough air for an air nozzle that requires 15 cu. ft. per second.
crosley95 posted 04-22-2002 02:43 PM ET (US)     Profile for crosley95  Send Email to crosley95     
spectrum recommends using acetone to thin the gelcoat.


Post New Topic  Post Reply
Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.