painting an outboard

[JimS123]

Re: painting an outboard

Well jim it's kinda hard to explain what going on because i have never done this before.So here is the best i can do and i hope you understand as i'm new to this.When i put the self etching primer on it had like a sandy look to it so i figured the paint would cover it up.Well thats not the case as it looks like sandy paint on it on not a smooth finish.

The only thing i think i can do is let it dry till tomorrow and sand down the paint one more time with like 800 or 1000 grit to smooth it out then clean with acetone then repaint one more time.Does this sound right.

I think if i sand down the paint a little it will come out much better.

Gee its awful hard to troubleshoot remotely without seeing the job!

The primer should be "flat", as opposed to semi-gloss or gloss. It should however be smooth. "Sandy" I can't imagine. Does your topcoat finish look rougher over the primed spots as opposed to the previosly painted spots?

I don't have your paint can in front of me so I don't know what the recoat times are. But I would guess that you can't paint tomorrow, or even sand for that matter. Wait a week before you do anything. If you paint too soon you will bubble, blister and lift the paint and you will end up having to completely strip the motor and start from scratch. Whatever you do, don't put acetone on it n ow.

If you could take a closeup pic of the sandy spots and what you have now it would certainly help.

 

[boater1234]

Re: painting an outboard

I used rustoleum self etching primer and it came out like crap.It was the primer as i just finished wet sanding it smooth and it came out beautiful.No more sandy looking spots at all.Also no the painted spots and the bare metal spots all came out the same,like crap.It may have been the can of paint my neighbor said.Tomorrow i'm going to finish wet sanding all the rough spots i could not see as it was getting dark and then acetone it and repaint it with 2 nice coats and i think it will be ok.

I think it may be ok i didn't put any acetone on it today,i'm going to give it overnight to dry and finish sanding the couple of small spots i missed as i got over 95% of it done already.If you think it won't work let me know,thanks.But by wet sanding it today i think it will ok.It looks a heck of alot better then before.I sanded almost all the way down to the primer again with only a little paint remaining as that was the only way it would come smooth.

 

[JimS123]

Re: painting an outboard

First of all, rattle can paint is no where near as durable as the original baked enamel on the engine. Thus, it is much less resistant to being dissolved by acetone. Secondly, if you just painted it, it certainly is not cured yet. If you can sand it without it balling up, consider yourself lucky and just leave the acetone alone.

If the paint is not cured fully tomorrow adding another coat of black will bubble it. You might get away with it but I wouldn't do it. Don't be in a hurry unless you have the time to do it over.

When I gave you suggestions before, I listed specific materials. The NAPA primer goes on smooth and does not require sanding, but requires recoating in 1 hour. You used Rustoleum. I never tried that before, that's why I didn't recommend it. I just looked on their web site and if I read the TDS correctly, sanding IS required. So maybe that's your problem. It should have specified recoating instructions on the can.

I've only painted one black Merc. Rustoleum topcoat worked fine over NAPA primer. The decals were also completely redone.

 

[boater1234]

Re: painting an outboard

The can of primer i used for this motor was exactly the same can i just touched up a 2008 8hp merc with and the same primer came out smooth,but for some reason this one didn't.

But anyhow it looks ok now.Well i will finish sanding it tomorrow and i will see what happens.I will go to napa and get their primer for future outboards but like i said i have used rustoleums self etching primer a few times before just to touch up paint problems on outboards and it came out nice without sanding.For some reason it came out nasty on this one which i have never seen before.

With the napa self etching do you have to sand with that one or it comes out smooth with no sanding?Also the paint i used on the engine is factory enamel quicksilver from the marina that i have also used before and it is an exact match.Well what i might do is just sand down to the primer and start all over with the paint as there is not that much paint on there,so i will let you know how it turns out.Thanks for all the help again and i will just have to practice to get better.

 

[JimS123]

Re: painting an outboard

NAPA SEP dries smooth with no need to sand.

With more info now....its easier to troubleshoot.

If the exact can of primer worked ok before but was sandy now, then you most likely have a reaction with the metal on the current motor. Could be a contaminant on the surface. As other have said, preparation is the key.

Also, if you used the same can, when you used it the time before, when you were done did you turn the can upside down to blow air thru the nozzle? Did you ever attempt to clear a clogged nizzle with a pin? Finally, what were the temp and humidity conditions when you painted yesterday?

 

[ezmobee]

Re: painting an outboard

Isn't Rustoleum's etching primer some kind of weird latex stuff? I'm a bit leary of it myself. Yours is the second bad result I've heard. I had good luck with Duplicolor's in a rattle can from Pep-Boys.

 

[JimS123]

Re: painting an outboard

The MSDS indicates its a solvent based alkyd. All of the SE types are zinc rich, but use phosphates instead of chromates.

This whole topic piqued my interest since I had thought that ZnCr was outlawed or at least removed from the retail market. Looking at Tempo and other products that say "chromate", but when you look at the formula its really a phosphate polymer.

Nothing like the old stuff for sure. When you chipped the paint the bond broke between the primer and the topcoat. You had to scrape pretty hard to get to bare metal. With today's "AE" stuff, the weakest link is the bond of the primer to the metal. Chipped paint always goes to bare metal!

 

[boater1234]

Re: painting an outboard

Well jim here is what i did.I wet sanded all the spots that i missed yesterday and it looks great,nice and smooth like a babys butt.I also see what your saying about letting the paint cure as it was soft.So what im gonna do is let it set till at least monday to give it 4 full days to cure which should be enough since i sanded down pretty far and there is very little paint as primer is showing.

Then monday one wipedown of acetone and the tack rag,and paint away as it should come out nice i hope.The last 2 days i have worked around 15hrs of trying to get every milk and crany of it to look as good as possible.I also preped my hood already as i degreased it,wet sanded it and sprayed it down with water and tomorrow i will do one wipe of acetone and paint away.There is very little paint on the cowl to begin with as i barely wet sanded it and the white showed through.This may turn out pretty good after all.Your right patience is the key and i will buy the napa primer or use the zinc chromate in the future for now on.Thanks to you and all the other people who helped me i might be able to tackle this.But like you said practice is the key.