I'm in the process of restoring my 21 SC. It's in my driveway(my only real option), disassembled down to hulls and crossbeams, upside down on saw horses, sanded, patched, sanded 4X, washed, rubbed with acetone, and I sprayed it with TS-780 Mono Epoxy Primer.

http://www.bottompaintstore.com/mono-ep ... 12339.html

I intend to paint it with this stuff (already purchased) when I sort out the primer mess.

http://www.bottompaintstore.com/revolut ... 12347.html

I used a HVLP sprayer and air compressor from Harbor Freight. I thinned it with acetone so it would spray.

My problem is that the primer came out pretty dusty/gritty/chalky. I have found that there may be several potential causes, none of which do me any good now.

How do I fix this? Can I just sand it with 220 grit? Something else? Do I have to sand it all off and start over? Just shoot me if that's the case.

Might my paint come out the same way? It's mid-upper seventies today. My driveway is shaded. I don't think it's that humid today.

Thanks for your advice,

Tim

Your links did not work. Just a wild guess here, but acetone may not be a suitable thinner for the TS-780. Also getting a wet application of paints requires balancing the gun for flow and air. It really pays to practice on a piece of cardboard before spraying. I searched for this paint and found, https://www.ipaint.us/pro…ts-780-mono-epoxy-primer. This stuff is not marine paint, and is intended for concrete, masonry tile and wood on garage and commercial floors. I'm probably missing something, but why floor paint? I have not seen that put on a boat.

If the primer dried to a sandpaper like condition, sand it off as completely as possible. you may need 180, and finish with240. You may need a larger tip for your spray-gun, otherwise the settings were wrong and the dry sandy appearance is too much air, and too little paint flow.

For finish coat, what are you using? The links won't work unless you use the URL tags.



Edited by tominpa on May 07, 2017 - 11:31 PM.

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Tom
NACRA 5.7 (1984 Sail 181)
Pennsylvania
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I'm not familiar with this primer, but it may also be a high build primer that is actually intended to be sanded with 220 to get the final surface. I used Awlgrip's 545 and it was a little gritty and chalky when first sprayed on. But it sands very easily and is great for block sanding. So just try a light sanding and see what it looks like after.

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dg
NACRA 5.2 #400
This End Up
Original owner since 1975
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You should prime and paint the boat with AWLGRIP !

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Doug Klem
Pensacola , Fl.
Blade F16
Prindle 18-2 w/spin
Prindle 18-2 x 3
Prindle 19 MX
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You cant use acetone to reduce epoxy primer . Sand it back down with 80 grit then prime with Awlgrip 545 epoxy primer . No reducer just primer and catalyst .

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Doug Klem
Pensacola , Fl.
Blade F16
Prindle 18-2 w/spin
Prindle 18-2 x 3
Prindle 19 MX
--

Alright, lessons learned. I sanded it down again. I talked to a couple people about setting up my gun. I had too much air. I purchased the proper thinner for the primer. I'll start over and wait even longer to get back on the water. It's a boat worth saving.

It's not so bad. I would encourage you to use an epoxy primer appropriate to the projects. I used Interlux Epoxy PrimeKote and DMGbear used Awlgrip 545 last year in our painting project. We both finished with Interlux Perfection.dmgbear sprayed and I rolled, and while his is perfect, mine gets complements. Here are the links:

http://=https://www.thebe…ms/viewtopic/topic/16330
https://www.thebeachcats.…ms/viewtopic/topic/16105
Anything you do in this finishing job will take twice as long as you think, and cost about 50% more than you think. The results will be worth it. Sanding will become something you can do in your sleep, cause you will do a lot of it.

What are you using as a finish coat? You realize the primer is for floors, right?



Edited by tominpa on May 10, 2017 - 08:26 PM.

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Tom
NACRA 5.7 (1984 Sail 181)
Pennsylvania
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All of these old boats are worth saving. Getting the result you want is also worth all of the effort. I won't tell you how many times I sanded my boat all the way back to glass, but you have a ways to go to catch up. I think spraying is the way to go too and I got it done with my HVLP setup. Two things that I found made a huge difference for myself as an amatuer sprayer, first to the extent possible get your hulls on their sides and spray them flat or as horizontal as possible. These are expensive finishes and they cure really hard and runs suck. 2nd figure out how to dramatically improve your lighting in the space you are working. These finishes are crazy sensitive to spraying too fast or too slow and without good lighting you won't know you screwed up until it is too late. I used the Interlux Perfection two part paint and that stuff has to be the pickiest paint I have ever dealt with. My next project will be with the Awlgrip 2000, which must be sprayed.

I did a bunch of video last year on my project and this one shows some of the stuff with the Perfection paint:

https://www.youtube.com/e…o=U&video_id=sjSstD7sRqo

This video above shows the roll and tip method, but then there are even more showing it getting sanded off and then going to the spray setup.

Good luck

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dg
NACRA 5.2 #400
This End Up
Original owner since 1975
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Quote

All of these old boats are worth saving.

sorry to disagree - some old soldiers deserve a proper burial (firing squad, dynamite, tnt, or small nuke device will work)

I agree that some boats do need to go to the boneyard to provide parts for other boats and boaters. I just have a high tolerance and know that some of these repairs are more easily managed than others, particularly when it relates to the fiberglass.

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dg
NACRA 5.2 #400
This End Up
Original owner since 1975
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