gelcoat vs paint

Rocky · Post by **Rocky** » Feb 6th, '09, 21:33

Hi guys, sorry I have not chatted for a while, been very busy! Anyway, I have on the stern topsides of my B31 some holes from non used hardware and also some wear through of gelcoat that I know the sun will be a detriment to. Question is, should I color match some imron or awlgrip and paint(all 9 feet between rubrail and inside cockpit) or go through the extra labor of gelcoating back there? I also have some wear through on flybridge flat area in front I need to protect from the sun. Thanks for the help in advance. Rocky.

p.s., I just completed my rudder shelves per Capt. Patric's tips, they ain't going anywere!!

CaptPatrick · Post by **CaptPatrick** » Feb 6th, '09, 22:35

Rocky,

Square foot for square foot, re-gelcoating is not only more labor, but also more expense in the long run. The big down side to re-gelcoating is adhesion to an old polyester substraight. You have to have a tie coat that will both stick to the old stuff and still accept the new gelcoat. The Gray Surfacing Primer by Hawk Eye Industries is an excellent polyester tie coat, but expensive and has a short shelf life. You have to buy it fresh and use it soon. Even in an un-opened can, I've had it harden prematurely in under 3 months, even keeping the can in a cool dark cabinet.

There's a lot of labor in sanding, compounding, and sealing the new gelcoat after it's been applied, which application in itself is a bitch because of the viscosity and difficulty in spraying it into a smooth surface finish. You'll sand off at least 20% of what you lay down. Maybe as much as 50% depending on your techniques.

Now the up side to re-gelcoating is that it will out last most paints by 2 to 1. That's if you've overcome the adhesion problems.

If you paint only selected areas, leaving the remaining surfaces gelcoat, you'll have to plan out your starting and stopping points carefully so that your boat doesn't look like a spotted pup. You also need to select a paint that is a repairable paint so that you can achieve a blend and a feathered edge. Imron is one of the best for this. Original Awlgrip would not be a choice I'd make under just about any situation. (I love Awlgrip in an engine space though...) The new "repairable/blendable" Awlgrips were formulated to compete with Imron type paints, but I've heard too many bad reports on Awlcraft 2000 to want to try it.

Just about all paints today can be color matched to a specific color sample. Awlgrip's Oyster is a pretty close match to the classic Bertram gelcoat and Imron can be matched to an Awlgrip color chip. Color matching new gelcoat is a nearly impossible mission. You'd be matching to old faded gelcoat and might be successful, but as the new gelcoat ages, the color will fade and that will cause a color difference between the new and the old. Paint won't fade as bad or as fast.

Br,

Patrick

Rocky · Post by **Rocky** » Feb 7th, '09, 10:35

Thanks Capt. Pat, I was also dredding having to remove the rear rubrail section for gelcoating, maybe with imron I could just tape off? So if you do not like the awlgrip for blending in, should I match the "Oyster" from awlgrip to imron? This sure does sound easier than gelcoating/matching to old. Any kind of flattening agent to use to match gelcoat's "not as shiny" characteristic? Thanks again, Rocky.

MikeD@Lightningshack · Post by **MikeD@Lightningshack** » Feb 7th, '09, 10:53

I re-gelcoated my entire bridge 2 years ago.

During the process I swore I'd never do it again. There were huge challenges every step of the way.

Spraying is difficult because your pot cures to a solid in minutes. So you have to move fast, make no mistakes and a have support with you.

When you are done spraying you end up with a fairly rough finish. Now you have to sand and polish for several days. If you make a mistake and sand too far, you will need to repair. The repairs are complicated because you need to buildup the whole area or you'll sand through again.

Ultimately I am glad I did it this way, it really looks terrrific. It is also a very forgiving and easy surface to repair or touch up. My painting skills were never on a professional level, and even when I higher a professional it never seems to go perfect. Theres is always a run drip or error that can never be easily repaired. With IMRON maybe this is not the case. But the good thing about the gelcoat is it is really easy to repair especially if you work with a standard unmixed color.

I would recommend just fixing the bad spots with gelcoat for now. The discolorizations won't look any worse than the looks of having a brand new painted transom on an older gelcoat boat. If that goes well you can always do more the same way.

Otherwise you wait until your ready to re-paint the entire topside. At that point you go with the IMRON.

I have some pictures on my website of my gel coat project.

Good Luck,

www.lightningshack.com

CaptPatrick · Post by **CaptPatrick** » Feb 7th, '09, 11:22

Rocky wrote:I was also dredding having to remove the rear rubrail section for gelcoating, maybe with imron I could just tape off? So if you do not like the awlgrip for blending in, should I match the "Oyster" from awlgrip to imron? Any kind of flattening agent to use to match gelcoat's "not as shiny" characteristic?

Masking out the guard rail will be OK for paint. Just get the Awlgrip color chip that best matches the color you want and take it to an Imron dealer to match it in Imron. Flatening agents are available, and that's going to open up another area of complication, How much to add to get a similar surface gloss as the old gelcoat. You'd have to experiment some and take careful notes as to what percentage of flatener you added to get what results.

I suggest that you clean and polish the boat as best you can and then use that surface condition and color as the control for what ever color and flatness you need to match.

Also, be aware that you can't just fill or paint/gelcoat over any spider cracking. It'll ghost back and continue to crack with age. Any spider cracking has to be sanded down to or very near the underlaying fiberglass...

Rocky · Post by **Rocky** » Feb 7th, '09, 11:24

Thanks for the input Mike, it does sound like a real chore with gelcoat for such a small area. Imron will be used for forward deck anyway, so I guess I should start at the stern!! Rocky.

CaptPatrick · Post by **CaptPatrick** » Feb 7th, '09, 11:27

Rocky, be sure not to miss the edited in "also" above...

DRIFTER31 · Post by **DRIFTER31** » Feb 7th, '09, 15:33

Capt10Pat......Have you seen this company{Mini craft from Fla.}They specialize in aersol gelcoat for repairs and match most boats if you know what the factory used. I bought two cans for the 1986Tiara for spot repairs. They come with a little tool to inject the hardner thru the spray hole and then you just put the spray nozzle back on and go with it. Seems perfect for small repairs.
Best Regards Troy

CaptPatrick · Post by **CaptPatrick** » Feb 7th, '09, 16:03

Troy,

I'm aware of the company, but have never used their products...

Br,

Patrick

bob lico · Post by **bob lico** » Feb 7th, '09, 21:51

capt. patrick your post brings up a good question.this is not my opinion but happens to be the absolute truth you cannot give away a boat in 2008 with a gelcote interior .i have seen 31bertram from elite marine your buddy boy and others with a beautiful gel-cote interior well you can`t sell that look to the ladies much to my dismay.they want soft like matte surface in conjuntion with marine wall paper like egg harbor,buddy davis,ocean,garlington even cabo a dedicated fishing boat must go with the flow or not make a sale.i will go with the ultrasuede ceiling but the rest is hard to swallow. to quote vic roy "what are we pussies" we are if we want to please the masses.moving right along can we apply gel-cote on the interior (all the pieces that are oem gel-cote) with a roller that would imitate a leather surface.no wheeling,no polish just a matte surface on top of some type of primer or could you just sand original with 220 grit.

Rawleigh · Post by **Rawleigh** » Feb 9th, '09, 09:09

I'm with you Bob! Gloss gelcoat or Awlgrip are my preferred interior finishes!!! Ease of cleaning and mildew resistance are my two most important criteria!

bob lico · Post by **bob lico** » Feb 9th, '09, 10:38

it is a damm shame rawleigh we have a left over 41' luhrs open. a buyer came aboard with his wife and as it turned out we have to cover the gel-cote in the cabin in order to make the sale.the monthly floorplan on that 2007 left over is 545.00 so we will go with the flow and wallpaper.she said it looked liked a mental asylum, sorry i have never been in one ---but i am working on it!!!like i said it is not what my personel taste is it what the masses want. at least the pussy who brings his wife with him before he sighs the dotted line.so the question is how do make the gel-cote look like the texture of the leather style headliner???? capt patrick i don`t know if you ever had to do this but your opinion would be appreciated.

CaptPatrick · Post by **CaptPatrick** » Feb 9th, '09, 12:32

Bob,

Only way I'd know to go about it would be to cover everything with a suitable fabric using pray adhesive. Some areas would be fairly easy to do, some could be a real pain in the butt. She sounds like an even bigger pain in the butt... A good custom auto upholsterer could make it look easy, but where do find one and how much is it gonna; cost? I'm talkin' about the guy who Chip Foose or Jessie James might use.

Br,

Patrick

Rawleigh · Post by **Rawleigh** » Feb 9th, '09, 12:37

Bob: It must remind her of one of her prior residences!!! LOL!

In Memory Walter K · Post by **In Memory Walter K** » Feb 9th, '09, 14:04

Gelcoat and hit with a fine foam roller?

In Memory Walter K · Post by **In Memory Walter K** » Feb 9th, '09, 14:07

After the first seasick person projectile vomits when sitting on the john with the door closed, she might like the ease of cleaning up the glossy walls with a hose and floor drain. There ARE some advantages.

bob lico · Post by **bob lico** » Feb 9th, '09, 18:26

actually that wallpaper ( that really is a deceiving describution) is very durable and is use on most sportfisherman today along with teak.we had a team from nautical seams come and look today.gentlemen there is nothing to say for $600,000 except "yes we can do that".you can clearly see the trend in boat shows ; ny,long island,atlantic city the everglades lx sells with real teak laminate on walls and galley and with wall covering in dinette and v-berth.like it or not this is the future.unless it is a single guy with speed on mind like fountain boats the other 90% of the market goes to the family guy on large center consoles.
walterk i will try the foam roller on my bert i am commited to gel-cote but will go for a leather look or matte surface.capt patrick i will go with wall covering with 3m 77 spray on wall adjacent to dinette and expose wall of bulkhead.

Raybo Marine NY · Post by **Raybo Marine NY** » Feb 10th, '09, 08:32

Bob- there are spray on textured finishes, like a ultra-suede finish, Alexseal makes a line of it, but honestly a semi gloss industrial paint with just the right type of roller will give you results very close to the suede finish and you wont have to spray it.

We have been on a interior kick this winter, lots of painting inside of boats with a roller, I got to say I have always been a spray guy, but the ease of the roller is so much better and when you do it properly give you results within 95% of spraying- unless you want a super smooth and shiny surface, then you have no choice but to spray.

Spraying inside of boats is a blind thing, once you start spraying it fogs out and its like spraying in a dense fog, at that point instinct takes over and you just go through the motions and hope it looks good when the overspray clears. I have tried using yellow lights ( like a fog light in a car ), having fans, etc, but nothing seems to clear the overspray out in the time you need it because the spraying goes much quicker then the overspray will evacuate.

Buju · Post by **Buju** » Feb 10th, '09, 08:49

Raybo,
Are ya using a conventional sprayer?
If so, have you ever considered going the HVLP route, at least for interior work? The overspray is so minimal (hi 80's transfer efficiency), would really be a huge advantage in that situation.
A open hatch, and a fan in the companionway blowing outward takes care of the small amount of overspray that does bounceback.

Raybo Marine NY · Post by **Raybo Marine NY** » Feb 10th, '09, 09:58

I use the most efficient spray gun on the market, it has one of the lowest CFM usage that I have found, its actually more efficient and complies to the strictist EPA regulations in the country- different states are much more strict then others.

Buju · Post by **Buju** » Feb 10th, '09, 13:39

Well Robbie, it's good you at least took the time to objectivley consider the advice...
I'm not going to pretend to do the volume of work you do, nor do I have the hours of experience under my belt that I assume you have. But, on the interiors that I have sprayed, I have never had to blind spray in a cloud of overspray as you describe.
Since you didn't bother to list what your "cremÃ© de la cremÃ©" equipment is, I have no way of doing any comparison... And I do know there have been vast improvements to conventional guns in the last few years.
But the very nature of conventional spray is old tech, and less efficient overall than HVLP. (HVLP generally atomizes between 2 to 8psi, 10psi on really viscous materials, whereas conventional spray generally atomizes between 35 to 80psi. Obviously the lower air pressure allows the higher volume (CFM) of material to hit the substrate at a much lower velocity than conventional equip, resulting in greatly reduced bounceback/overspray).

I've got no idea, or interest, in what NY laws are pertaining to spray equipment. But I am aware that my little unit passes California's stringent SQAMD standards with flyin colors. My understanding is that CA has always been the toughest on these issues.
I'm in no way saying that I am right, and you're wrong... Simply handing out some potentially helpful advice based on real world experience and observations. Could be beneficial to reconsider, and do a little research on HVLP... might not be.
I understand that you don't want to listen to some joker down in the Keys with the goofy username...

But what about the EPA? I think they seem to know a thing or two about the subject:
http://www.epa.gov/dfe/pubs/auto/spraygun_success/

Every automotive body shop wants to use paints efficiently, save money, and work safely. No shop wants to take a chance on the quality of a finish and have to redo a paint job. And there lies the promise and challenge of HVLP (high-volume low-pressure) spray guns. Capable of greatly increasing paint transfer efficiency, decreasing costs, and creating a healthier workplace, the HVLP spray gun seems an obvious choice. Yet many painters have been slow to switch from conventional guns, objecting to the feel of the HVLP spray gun and its spraying performance, especially when applying clear coat.

Research demonstrates that HVLP spray guns can achieve far greater transfer efficiency (over 60% with good technique) than conventional spray guns. Higher transfer efficiency means less of what you don't want: paint overspray, mists that a painter might breathe, emissions to the communityâ€”and more of what you do want: savings on paint and an improved bottom line

It's a quick little read, check it out.

Raybo Marine NY · Post by **Raybo Marine NY** » Feb 10th, '09, 14:19

I listen to everyone, I dont think anyone is a joker when we are discussing serious matters, if we were talking about our favorite cocktails or swimsuit model then thats a different story.

My gun is a Devilbiss gfg-670plus gun, I switched from a Devilbiss GTi gun, I had a protype milenium kit on the GTi gun, so it was basically the newer milenium gun.

HVLP guns require quite a bit of CFM to properly atomize the paint, the gti was something like 16cfm, where the 670 is 9-11lbs.

The plus gun is actually more efficient then HVLP.

http://www.autorefinishdevilbiss.com/do ... -%20CO.pdf

http://www.autorefinishdevilbiss.com/do ... -%20CO.pdf

funny enough this is the interior that I was spraying blind in, with the windows in place, the front hatch open to allow air in, and the bulkhead windows out with a fan and hose hooked up in the window opening connected to a exaust fan you could not see too well. Maybe "blind" was a bit of a stretch, but I would not suggest to someone who is not familiar with a spray gun to spray large areas inside a boat because visibility is not great.

When I sprayed the other side, the port side with the couch, that was worse because at that point the bulkhead windows were in place and could not be removed.

whenever I hear of someone spraying inside the boat, this comes to mind and makes me have pity for the person involved.

Buju · Post by **Buju** » Feb 10th, '09, 15:43

Thanks for taking the time Robbie. Interesting, sounds like a gem of a gun, and certainly one of those "vast improvements in conventional spray equip" that I'm just vaguely aware of. Could call it a LVHP (low volume high press.)..
I confess to be prejudiced and not up to speed on conventional equip.

Don't know if I'd flat out say:

The plus gun is actually more efficient then HVLP.

as opposed to:

the DeVilbiss GFG-670 (Plus) spray gun is capable (under specified
operating parameters) of achieving equivalent or better transfer efficiency than HVLP spray equipment. Based on this review, the Division approves its use under the following conditions:
1. The air pressure supplied to the DeVilbiss GFG-670 (Plus) spray gun is equal to or less than 40
pounds per square inch gauge (psig).
2. An appropriate spray gun-mounted needle valve and pressure gauge, provided by ITW is
attached to the DeVilbiss GFG-670 (Plus) spray gun and is in good working condition during
actual operation. The gauge must clearly indicate that the maximum air pressure to be used is
40 psig and the spray gun must be operated as such.
3. A clearly visible permanent label specifying that the inlet air pressure shall not exceed 40 psig is
attached to all DeVilbiss GFG-670 (Plus) spray guns used; and they must be operated as such.
4. ITW shall supply written notification to each individual purchasing a DeVilbiss GFG-670 (Plus)
spray gun for use within the Denver 1-Hour Ozone Area indicating that its use is only
approved when operated under the conditions specified in this letter.
5. The operator can produce a copy of this letter for inspection by the Division or local agency
personnel upon their request.
6. Only the DeVilbiss GFG-670 (Plus) spray gun model is covered by this approval.

And don't kid yourself, I'm definatley a joker. But my advice was/is sincere.

Raybo Marine NY · Post by **Raybo Marine NY** » Feb 10th, '09, 16:40

the name HVLP is always a bit confusing to some, when you compare the amount of air that moves through a HVLP versus a conventional spray gun, takes alot more air to keep a HVLP going. You realize this when you first switch to HVLP and you have older equipment or a smaller compressor.

My truck mounted compressor unit can barely keep up with my HVLP guns, I remember having to wait for air pressure when I was painting the hull on a brand new 50' at the local marina, when I switched to my plus gun I had no air problems.

Same thing at the shop, if someone was using a DA, let alone 2 guys using air tools, I would run out of air if I was spraying a hull, that all went away with the plus gun.

It is always suggested that you use larger diameter air hoses with high flow fittings when switching over to HVLP.

I guess I take DeVilbiss selling that the plus technology is better then HVLP, I dont see why they would fib as they own 6 different brands of guns and sell both HVLP, Plus, and the newest Trans-Tech High Efficiency Technology that I have yet to try.

Experience the Power of PLUSÂ®...

Powerful atomization - twice he energy available in HVLP guns
Powerful productivity - super fast fluid flow for high speed painting
Powerful efficiency - equal to or better than HVLP transfer efficiency

What is High Efficiency?
There is no legal designation for High Efficiency spray guns, unlike HVLP. High Efficiency compliant guns are defined as guns that have been proven to deliver equal to or better transfer efficiency than HVLP. The PLUSâ„¢ gravity gun has been approved by the South Coast Air Quality Management District (SCAQMD) along with most of the Air Quality Management Districts throughout the United States.

http://www.autorefinishdevilbiss.com/products.php?pg=1

for the record I also use cheapo astro conventional guns for gelcoat and primers, I have a HVLP 2 quart and a 2 gallon pressure pot set up, and for smaller jobs I use a DeVilbiss SRI-W touch up gun and I have a cheapo astro suction feed touch up gun that can actually spray pretty good non-skid repairs- that little gun puts out a TON of material for its size, it can get dangerous if you forget what your doing.

And for graphics touch ups I have a Iwata air brush.

For the money you cant beat the astro guns, they are SUPER simple inside too, very little to clean

Rocky · Post by **Rocky** » Feb 10th, '09, 22:03

Raybo, could you tell me what gun you would buy for applying the imron (when the weather warms up) on my aft topside? I do not have a professional gun as of yet, and only plan on small area jobs like this at a time.I do have a 20 gallon air compressor IR, that can keep up with my cheap automotive gun. Would appreciate the advice.
Rocky.

Buju · Post by **Buju** » Feb 10th, '09, 22:28

the name HVLP is always a bit confusing to some, when you compare the amount of air that moves through a HVLP versus a conventional spray gun, takes alot more air to keep a HVLP going. You realize this when you first switch to HVLP and you have older equipment or a smaller compressor.

The name is actually really acurate... High Volume, Low Pressure. Meaning there is actually a higher volume (10 to 25 CFM) but the material properly atomizes at a much lower pressure (2 to 10 psi).
Now, I have never used a "HVLP Gun" like the ones you're refering to. Meaning: a hvlp conversion for conventional spray, aka a "direct hook up gun" that attaches to an air compressor.
All of the experience I have is based on a self contained tangential multistage turbine, like the Capspray9900 I posted the pic of above. Very difficult not to be extremely happy with one of those units.
Some basic literature on 'em:
http://209.85.173.132/search?q=cache:Ea ... cd=1&gl=us

I can understand the frustration of guys who buy a hvlp gun for their compressor, and find out their compressor doesn't put out enough air to properly use the gun. I beleive a 5hp compressor is the bare minimum to use a direct hookup gun.
Definatley need larger diam. hoses... the hose on my Capspray 9100 is about 1" or more in diameter. Remember, we're not looking for pressure, but to transfer a higher volume of air.

Truth be told, I'd love to meet up with you. I bring my capspray9100, you bring your devilbis plus. We have a junk boat, a few different coatings (imron, awlgrip, perfection, etc) and a 12 pack. I'm willing to bet that we'd both walk away pleasantly surprised, and with newfound and beneficial knowlege of the workings of each system.

Raybo Marine NY · Post by **Raybo Marine NY** » Feb 10th, '09, 22:40

most people dont read into the meaning of HVLP, they just know it stands for high volume, low pressure- so they assume it means it does not require alot of air.
I have always wanted to try one of those self contained units, the fact that it has a 1" hose is very interesting, that in itself does wonders to keep up with the air requirements of the gun compared to the 3/8 line with restrictive fittings that most people use.

Rocky- if your just spraying a few small items my advice would be to stick with the gun you have, spend your money elsewhere.

Rocky · Post by **Rocky** » Feb 10th, '09, 23:25

Raybo, thanks for that advice. I guess the gun I have will do. It's done a few cars over the years, including a large "boot stripe" around the cabin of a Skipjack25 in imron. Turned out good.
Rocky.

bob lico · Post by **bob lico** » Feb 10th, '09, 23:29

one of the most informitive post ever written.this sandbox is by far the best on the internet.that being said i like the idea of roll on semigloss for the interior gel-cote surfaces.just for one minute lets look at the women walking in and out of the boat at the boat show.she is coming from a house that does NOT have high gloss white walls so what makes you think she is going to like your bertram cabin in gel-cote. mind you she just step out of a 45 bertram with teak or cherry wood cabinetry and wall covering with suede ceiling.look at that beautiful half round door capt. patrick made for buddy boy if it was laminated with teak veneer instead of gel-cote it would soften up the harshness of the bright gel-cote in the rest of the cabin.again not my taste just informing those selling a cabin boat you have to appeal to the other half.

Buju · Post by **Buju** » Feb 11th, '09, 06:51

Sorry 'bout the hijack Rocky...

Rocky · Post by **Rocky** » Feb 11th, '09, 09:59

That's alright Buju, I read everything interesting you guys put down, always entertaining. I've got a HVLP for the house, it comes with a 1inch dia. hose for a high volume of air, low pressure and boy does it lay it on. I don't like the bulky hose to fight with though. Rocky.

bertram31.com

gelcoat vs paint

gelcoat vs paint

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