Announcements
New Discussions
Worrell 1000 Ground Crew Finder
by John Williams. 02/18/20 06:50 PM
9 foot inflatable boat
by AudreyGrace. 02/18/20 12:58 AM
Inflatable dinghy Canada
by AudreyGrace. 02/11/20 03:50 AM
Bringing back the cat
by dave mosley. 02/03/20 08:12 AM
Worrell 1000
by John Williams. 01/29/20 04:38 PM
F85SR Concept Boat
by phill. 01/29/20 03:44 AM
Previous Thread
Next Thread
Print Thread
Rate Thread
Hop To
Preval Sprayer and Flex-Mold #283408
08/30/16 10:10 AM
08/30/16 10:10 AM
Joined: Jan 2004
Posts: 330
S
srm Offline OP
enthusiast
srm  Offline OP
enthusiast
S

Joined: Jan 2004
Posts: 330
Anyone ever used a Preval Sprayer for spraying gelcoat? My one friend said they don't work very well, but he's a professional fiberglass repairman so he's used to using high end equipment. I just have a few small areas of deck that I'm putting back together and can't really justify buying a compressor and spraying equipment. So my other options are to try to brush on gelcoat or see if my buddy can spray it for me.

Same question regarding Gibco Flex-Mold for repairing non-skid - anyone have experience with this? It's kind of pricey at $54 for a 1' x 1' square but looks like it could be the best option for matching the original non-skid texture on the deck.

sm

-- Have You Seen This? --
Re: Preval Sprayer and Flex-Mold [Re: srm] #283409
08/30/16 10:46 AM
08/30/16 10:46 AM
Joined: Nov 2011
Posts: 381
SE MI / NE IN
rehmbo Offline
enthusiast
rehmbo  Offline
enthusiast

Joined: Nov 2011
Posts: 381
SE MI / NE IN
With regard to the Preval sprayers, one of my good friends (John Bauldry) uses them almost exclusively and had showed me how to do it. They work amazingly well for small jobs. Have to thin the gel with acetone to get it to spray smoothly. The acetone vaporizes before the gel hits the boat so it doesn't impact application very much.

As to the quality of the result - I did a decent size 4"x6" repair on the side of my boat last summer and I challenge anyone to find it.

Last edited by rehmbo; 08/30/16 12:33 PM.

Jeff R

H18, C2 USA1193
cramsailing.com
crescentsail.com
Re: Preval Sprayer and Flex-Mold [Re: srm] #283410
08/30/16 12:23 PM
08/30/16 12:23 PM
Joined: Jan 2004
Posts: 330
S
srm Offline OP
enthusiast
srm  Offline OP
enthusiast
S

Joined: Jan 2004
Posts: 330
Good info, thanks!

How much life do you typically get from one canister? I have four areas to spray - two about 8" x 10" and two about 5" x 8".

sm

Re: Preval Sprayer and Flex-Mold [Re: srm] #283411
08/30/16 12:33 PM
08/30/16 12:33 PM
Joined: Nov 2011
Posts: 381
SE MI / NE IN
rehmbo Offline
enthusiast
rehmbo  Offline
enthusiast

Joined: Nov 2011
Posts: 381
SE MI / NE IN
It lasted a lot longer than I expected - I generally ran out of gel in the jar long before it began to affect spray-ability. I guess it depends on temperature and how much hardner you mix in.

I think you could theoretically clean them out for reuse. But at $5 each, its hardly worth the labor.

Each coat had to cure overnight before sanding. In my case 3 coats = 3 preval sprayers.


Jeff R

H18, C2 USA1193
cramsailing.com
crescentsail.com
Re: Preval Sprayer and Flex-Mold [Re: srm] #283412
08/30/16 12:38 PM
08/30/16 12:38 PM
Joined: Nov 2011
Posts: 381
SE MI / NE IN
rehmbo Offline
enthusiast
rehmbo  Offline
enthusiast

Joined: Nov 2011
Posts: 381
SE MI / NE IN
I also did the daggers and rudders on our club's Tiger a couple years ago. One jar full was more than enough for a solid coat on one side of each. I did 2 coats on each side, so in the end it was 4 Preval sprayers.

Proper surface prep and sanding is always key. Spraying gel is the easy part. smile


Jeff R

H18, C2 USA1193
cramsailing.com
crescentsail.com
Re: Preval Sprayer and Flex-Mold [Re: rehmbo] #283413
08/30/16 03:01 PM
08/30/16 03:01 PM
Joined: Jun 2002
Posts: 1,658
Florida Suncoast, Dunedin Caus...
catman Offline
Pooh-Bah
catman  Offline
Pooh-Bah

Joined: Jun 2002
Posts: 1,658
Florida Suncoast, Dunedin Caus...
Actually I would use medium Lacquer thinner instead of acetone. Thin it just enough to get it to spray.

As far as the nonskid goes, I waxed a area of the good non skid and laid some lightweight glass on it and make my own pattern. Did it on a hobie 18 with fairly good results. Not perfect but good.


Have Fun
Re: Preval Sprayer and Flex-Mold [Re: srm] #283414
08/30/16 04:05 PM
08/30/16 04:05 PM
Joined: Jan 2004
Posts: 330
S
srm Offline OP
enthusiast
srm  Offline OP
enthusiast
S

Joined: Jan 2004
Posts: 330
Not a bad idea regarding the non-skid. Considering I have 2 TheMightyHobie18's, I could just splash a mold off the good boat and use it to mold the gelcoat on the one I'm fixing.

sm

Re: Preval Sprayer and Flex-Mold [Re: srm] #283416
08/31/16 07:37 AM
08/31/16 07:37 AM
Joined: Jun 2001
Posts: 12,310
South Carolina
Jake Offline
Carpal Tunnel
Jake  Offline
Carpal Tunnel

Joined: Jun 2001
Posts: 12,310
South Carolina
Originally Posted by srm
Not a bad idea regarding the non-skid. Considering I have 2 TheMightyHobie18's, I could just splash a mold off the good boat and use it to mold the gelcoat on the one I'm fixing.

sm


You can also use 100% silicon caulk to make a non-skid pattern mold with...it has the added benefit of being flexible so you can apply that pattern to other areas of the boat that aren't necessarily the same shape as the area you made the mold from. You'll need some sort of mold release to get the silicon to remove cleanly...can't recall what the right stuff is at the moment, though. I'm sure the internet can help.


Edit...welp, here you go: http://www.martha.net/2014/05/making-a-100-silicone-caulk-mold/


Jake Kohl
Re: Preval Sprayer and Flex-Mold [Re: srm] #283509
09/16/16 07:50 PM
09/16/16 07:50 PM
Joined: Jan 2004
Posts: 330
S
srm Offline OP
enthusiast
srm  Offline OP
enthusiast
S

Joined: Jan 2004
Posts: 330
Any recommendations on getting the preval to spray better? Today was my first attempt. I thinned the gelcoat with styrene at about 10% and got a lot of spatter. I added a bit more and it improved somewhat but still got a fair amount of spatter and it seemed to be having a tough time sucking in the gelcoat. Thin it more? I believe the recommendation I read was to thin between 10-20%. Should I go more? I'm also wondering if the surfacing wax I added played a roll in how well it sprayed.

sm

Re: Preval Sprayer and Flex-Mold [Re: srm] #283511
09/17/16 03:56 PM
09/17/16 03:56 PM
Joined: Dec 2001
Posts: 5,590
Naples, FL
waterbug_wpb Offline
Carpal Tunnel
waterbug_wpb  Offline
Carpal Tunnel

Joined: Dec 2001
Posts: 5,590
Naples, FL
not sure since I never used wax in the gelcoat mix, but that could possibly be it..

I've sprayed thinned gelcoat with the Prevail for smaller jobs with good results.

Thinned it to just a little thicker than car-paint consistency and sprayed several layers to build thickness (letting it flash off between coats), and then spraying that green stuff that smelled like chloraseptic to seal the top coat (mold release)

Course, I'm in the tropics (high heat/humidity) so flashing off took about a minute..

Last edited by waterbug_wpb; 09/17/16 03:57 PM.

Jay

Re: Preval Sprayer and Flex-Mold [Re: srm] #283513
09/17/16 07:59 PM
09/17/16 07:59 PM
Joined: Jan 2004
Posts: 330
S
srm Offline OP
enthusiast
srm  Offline OP
enthusiast
S

Joined: Jan 2004
Posts: 330
Thanks for the reply, but not having ever worked with car paint, that description isn't all that helpful for me. Approximately what percentage are you using gelcoat to styrene? 50/50, 75/25, 90/10?

sm

Re: Preval Sprayer and Flex-Mold [Re: srm] #283518
09/18/16 09:36 AM
09/18/16 09:36 AM
Joined: Jun 2002
Posts: 1,658
Florida Suncoast, Dunedin Caus...
catman Offline
Pooh-Bah
catman  Offline
Pooh-Bah

Joined: Jun 2002
Posts: 1,658
Florida Suncoast, Dunedin Caus...
Two things. Use medium lacquer thinner not styrene. Do not use the wax. The wax clogs the sprayer. Spray the area with PVA right after the last coat or Hair spray. I have gel-coated many boats and have tried many methods.


Have Fun
Re: Preval Sprayer and Flex-Mold [Re: srm] #283523
09/18/16 03:03 PM
09/18/16 03:03 PM
Joined: Jan 2004
Posts: 330
S
srm Offline OP
enthusiast
srm  Offline OP
enthusiast
S

Joined: Jan 2004
Posts: 330
Are you also using the Preval to spray the PVA?

sm

Re: Preval Sprayer and Flex-Mold [Re: srm] #283525
09/19/16 06:12 AM
09/19/16 06:12 AM
Joined: Jun 2002
Posts: 1,658
Florida Suncoast, Dunedin Caus...
catman Offline
Pooh-Bah
catman  Offline
Pooh-Bah

Joined: Jun 2002
Posts: 1,658
Florida Suncoast, Dunedin Caus...
Yes.


Have Fun
Re: Preval Sprayer and Flex-Mold [Re: srm] #283526
09/19/16 08:35 AM
09/19/16 08:35 AM
Joined: Dec 2001
Posts: 5,590
Naples, FL
waterbug_wpb Offline
Carpal Tunnel
waterbug_wpb  Offline
Carpal Tunnel

Joined: Dec 2001
Posts: 5,590
Naples, FL
Originally Posted by srm
Are you also using the Preval to spray the PVA?

sm


use it in a separate prevail sprayer

And car paint is usually thinner than house paint. Does that help?

Think maybe hot pancake syrup?? Flows relatively quickly, but leaves a residue in the jar.


Jay

Re: Preval Sprayer and Flex-Mold [Re: srm] #283527
09/19/16 08:37 AM
09/19/16 08:37 AM
Joined: Dec 2001
Posts: 5,590
Naples, FL
waterbug_wpb Offline
Carpal Tunnel
waterbug_wpb  Offline
Carpal Tunnel

Joined: Dec 2001
Posts: 5,590
Naples, FL
Originally Posted by srm
Thanks for the reply, but not having ever worked with car paint, that description isn't all that helpful for me. Approximately what percentage are you using gelcoat to styrene? 50/50, 75/25, 90/10?

sm


I can't be sure of the exact ratio, since the gelcoat/additives/pigment(s) I was using may be different than yours. I went for the viscosity rather than an exact ratio.


Jay

Re: Preval Sprayer and Flex-Mold [Re: srm] #283533
09/20/16 10:30 AM
09/20/16 10:30 AM
Joined: Jan 2004
Posts: 330
S
srm Offline OP
enthusiast
srm  Offline OP
enthusiast
S

Joined: Jan 2004
Posts: 330
OK. Thanks, I've been messing around with it. I used the preval to spray the PVA and it worked relatively well, so I won't put wax in the gelcoat anymore. Still trying to figure out exactly how much to thin the gelcoat, but I'll figure it out.

One thing I noticed, the preval really doesn't seem to have a lot of pressure when spraying. However when I was cleaning it out afterward, I flipped it over (like you would do when cleaning a can of spray paint) and the thing blasted out a nice powerful plume. Would be nice if it had that kind of power when spraying upright.

sm

Re: Preval Sprayer and Flex-Mold [Re: srm] #283534
09/20/16 04:10 PM
09/20/16 04:10 PM
Joined: Jun 2002
Posts: 1,658
Florida Suncoast, Dunedin Caus...
catman Offline
Pooh-Bah
catman  Offline
Pooh-Bah

Joined: Jun 2002
Posts: 1,658
Florida Suncoast, Dunedin Caus...
It takes a bit of fooling around. You can thin it more. Just takes more coats to achieve coverage.


Have Fun

Moderated by  Damon Linkous 

Search

Who's Online Now
0 registered members (), 29 guests, and 316 spiders.
Key: Admin, Global Mod, Mod
Newest Members
wgilmour, Jacob7876, Wozza, kvc0615, CaptainAhab
8007 Registered Users
Top Posters(30 Days)
phill 1
Forum Statistics
Forums26
Topics22,377
Posts266,974
Members8,007
Most Online1,650
Sep 10th, 2019
--Advertisement--
Powered by UBB.threads™ PHP Forum Software 7.7.1