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voodoochile

baltoplate - HVLP spraying

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I'm following up a discussion from a year or so ago re spraying Baltoplate/Offshore. Today we sprayed 3 coats of Balto on the bottom of our 38' boat using a mid grade Accuspray HVLP gun. We thinned the Balto w/216 thinner 25% the first coat, then 30% or so the second and third. We got a very nice finish with very little orange peel, more of a suede or flat finish that will be very easy to wet sand. We were using 15# pressure at the gun and had negligible overspray even with the 30% thinning. We used a tyvek suit and hood and a respirator but it was almost unnecessary. For prep we had longboarded w/120grit and wiped down with MEK. The MEK actually dissolved the top layer of old paint so I think the bond should be very good. MEK worked great cleaning the equiptment. The 216 thinner smelled like Xylene/Xylol which would probably work for a thinner. The 216 likely has some retardant in it to slow down the drying. Using the 216 we were able to re-coat within 20 min. The manufacturer does not recommend HVLP and there was a bit of negative feedback re not following recommended application, but the HVLP put more paint on the bottom with MUCH, much less overspray. We used barely 1.5 gallons of thinned Baltoplate for 3 coats. At +/- $270 per gallon and VOC what it is, we will not use anything other that HVLP in the future. Also, we were pressed for time last year and did not put new paint on the bottom, opting to go 2 seasons in the moderatly salty fairly polluted (ie lots of slime growth) lower Chesapeake - Hampton Roads - Hampton River. We are a race boat and scrubbed at least bi weekly throughout the summer. The bottom still looked great when we hauled and had no evidence of shell growth and came perfectly clean with a light power wash on the lift. Needless to say, we won't be wasting time and $ on yearly painting in the future.

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HVLP? Compressor? grin why not the airless sprayer from Home Depot? Works real well as long as you keep the can full.

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I'm following up a discussion from a year or so ago re spraying Baltoplate/Offshore. Today we sprayed 3 coats of Balto on the bottom of our 38' boat using a mid grade Accuspray HVLP gun. We thinned the Balto w/216 thinner 25% the first coat, then 30% or so the second and third. We got a very nice finish with very little orange peel, more of a suede or flat finish that will be very easy to wet sand. We were using 15# pressure at the gun and had negligible overspray even with the 30% thinning. We used a tyvek suit and hood and a respirator but it was almost unnecessary. For prep we had longboarded w/120grit and wiped down with MEK. The MEK actually dissolved the top layer of old paint so I think the bond should be very good. MEK worked great cleaning the equiptment. The 216 thinner smelled like Xylene/Xylol which would probably work for a thinner. The 216 likely has some retardant in it to slow down the drying. Using the 216 we were able to re-coat within 20 min. The manufacturer does not recommend HVLP and there was a bit of negative feedback re not following recommended application, but the HVLP put more paint on the bottom with MUCH, much less overspray. We used barely 1.5 gallons of thinned Baltoplate for 3 coats. At +/- $270 per gallon and VOC what it is, we will not use anything other that HVLP in the future. Also, we were pressed for time last year and did not put new paint on the bottom, opting to go 2 seasons in the moderatly salty fairly polluted (ie lots of slime growth) lower Chesapeake - Hampton Roads - Hampton River. We are a race boat and scrubbed at least bi weekly throughout the summer. The bottom still looked great when we hauled and had no evidence of shell growth and came perfectly clean with a light power wash on the lift. Needless to say, we won't be wasting time and $ on yearly painting in the future.

 

What size needle and aircap? I have an Accuspray gun and Axis HVLP turbine that I've used for spraying primer and topcoat.

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As the proper thinner is 355 I am concerned about what that much lacquer thinner (216) may have left in the final applied product .

 

And I look foreword to reading next years report

 

And the next

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216 Just seems like the wrong thinner

 

355 is xylol, ethyl-benzene , methylisobutyl ketone, diacetone alcohol ,

 

216 only has the first two ingredients and that just seems like too much xylol

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355 scares the fuck out of me!!!! I hate even being around it.

EVERY use involves>>>> New mask cartridges, Tyvek suit, monster exhaust fan, and I go sailing, jogging, or to the gym for a long indoor bike ride any time I use the shit.

Same for 202 solvent wash or any urethane paint job.

I don't care if I finish at midnight and stay at the gym till three am. I need that flush out to live!!!!

 

After dealing with that shit I figure the best protection is to run the heart and lungs close to redline for at least an hour just to begin the flushing process

 

That shit seems to penetrate right through the skin

 

 

Maybe a sprayed baltoplate job is a little smoother than our best efforts with a roller but as the years pass I am less and less inclined to give up some lifespan so somebody can sail a tad faster.

Spray jobs involving nasty solvents and me are becoming more and more expensive and Jess and less frequent.

 

Gelcoated topside refinishes are also lots safer for me than urethanes as the chemicals involved are sooooooo much less horribly toxic

 

 

If you play with chemicals whose safety sheets read like Twinkie wrappers you damn certain better do more than just respect them

 

Fear and loathing is a good start

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just a dumb solvent question / slight hijack: the old rule of thumb is that "oily rags" used on turpentine/varnish/paint thinner need to be hung out to prevent spontaneous combustion. Does that apply to these things like 216 / 355, or is it heavier oils that do that?

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As the proper thinner is 355 I am concerned about what that much lacquer thinner (216) may have left in the final applied product .

 

 

He burnt the paint.

 

You burnt the paint hoss. Shooting out that much thinner screws everything up. You can get passable results rolling, thinned that much, but when the thinner and paint are atomized (through your HVLP) and hit the atmosphere, it does some shit chemically I'm not smart enough to understand and ruins the finish. You get a matte/flat finish.

 

I do industrial coatings.

 

There are three things I recommend and won't spray without

Following the directions to a T

Oversize compressor

High-flow fittings

 

I bet you guys put a hurtin' on your compressor.

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Baltoplate is a flat finish anyway. I am more concerned about the remaining thinner ( not evaporated) and what it does to the durability of the vehicle

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I hear your concerns. In the past we thinned 10% or so but were not getting the finish we wanted. Might have been our equip. or the tip size? Anyway, previous jobs have lasted 2 years with no cracking or flaking. I will say that we are pretty aggressive in our prep - air file/longboard w/120 to cut away a good bit of the old paint then a full wipedown with MEK. I'll let you know how it looks this winter.

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In the past we thinned 10% or so but were not getting the finish we wanted..

What kind of finish were you after that adding more thinner was the answer? You just wanted to make the job easier using HVLP and I don't blame you. Next time, just rent a pot gun, it's all you needed anyway. Did you hit the 2 mil dry thickness mark?

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We thin a lot and roll with a 3/16 roller. The paint sags its way to nearly as smooth as we can make bitching a spray gin and we don't have those tough areas near the keel from spraying over the dusty edges of other passes.

And the only material we purchase that does not vend up months boat is what is stuck in the roller. Or splatters when we roll too fast

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In the past we thinned 10% or so but were not getting the finish we wanted..

What kind of finish were you after that adding more thinner was the answer? You just wanted to make the job easier using HVLP and I don't blame you. Next time, just rent a pot gun, it's all you needed anyway. Did you hit the 2 mil dry thickness mark?

Figgy. In the past we've gotten a grainy finish from the heavy spray that dries quickly before laying down. The HVLP for sure puts more paint on the bottom and less in the air, though Gouv has a point re rolling where it all goes on the bottom. The thinning helped with the spray texture - it was smoother than roller texture - and we put on 3 coats over a period of about an hour and a half( 38' boat). We then start with 220 wet or dry to knock down the high spots and proceed to 320, 600, 1000 to complete the polishing. We use the wet and dry on a drywall sanding pad on a roller pole which applies even pressure and gives great leverage and reach when sanding. Two guys sand while one other guy sprays down to keep them going. I've used the Wagner painters in the past, but they don't give the finish of a good gun with variable size tips and pressure.

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What do you think about a pressure pot conventional vs siphon hvlp.

All the hvlp guns ( gravity feed) I have can't be inverted enough to paint the flat stern section. Or am I missing some kind of a trick here?

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We have used my old Accuspray 10 gun setup which has a 2 liter pressure pot to spray the Awlgrip bottom paint. Other than a gravity gun, which is useless for bottoms, the pressure pot is the way to go. Unfortunately unless you have a specific Accuspray turbine that has a mini air compressor on board. It won't work. You need the turbine for the gun and the compressor for the fluid. Theoretically you could use a small compressor for framing guns as long as you put a good filter on it. You can mess around with the air caps and tips and use more pressure so you don't have to thin down the material as much with an old school siphon gun.

 

We have had very good results with that rig. I would use an airless spray like the house painters use if I had to do a bottom today. You can get reasonable results spraying enamel paints on doors and cabinets. Certainly good enough for a bottom. They are relatively inexpensive compared to a good HVLP turbine rig.

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What do you think about a pressure pot conventional vs siphon hvlp.

All the hvlp guns ( gravity feed) I have can't be inverted enough to paint the flat stern section. Or am I missing some kind of a trick here?

Our pot has a 4' hose to the spray head so it sprays in any position.

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