Alternative to spray paint?

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Eugene

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Here is question for experienced guys. I used spray paint to finish up my plug for engine cowling. Really, really didn't like it for a number of reasons.

This project is simply too large for spray cans. Almost like trying paint small car this way!
Every can is giving me different spray pattern and one was actually spitting small chunks of paint occasionally. Used four cans and really didn't fill even small scratches and absolutely no buildup with nothing to sand. Will have to repeat this procedure possibly 3-4 times. Made absolute mess in my rental hanger and feel guilty already.

Wondering if anybody tried to roll automotive paint to accomplish same thing? Maybe even use high-quality brush? If you have thick enough layer, you can send it down and make it perfect. I think....

But, at this point I am wondering how would automotive paint react to what I have there already?

Any input is appreciated!

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Daleandee

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Wondering if anybody tried to roll automotive paint to accomplish same thing? Maybe even use high-quality brush? If you have thick enough layer, you can send it down and make it perfect. I think....
Never used auto paint but 3 part marine paint worked well for me:


FWIW ...
 

Geraldc

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For making a plug I have brush painted 2 part auto primer filler and then sanded and waxed.
 

Eugene

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For making a plug I have brush painted 2 part auto primer filler and then sanded and waxed.
I am not sure if automotive paint will go safely over what I have already on it? I am trying to determine what kind of paint was in my spray can, but unsuccessful so far.

 

crackle

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If it came out of a can it will be solvent based and probably susceptible to redissolve on the application of subsequent coats, especially if applied in thick layers... The only safe way to test what you want to apply over it is to spray a scrap panel and then apply prospective coatings over it to look for wrinkling etc. You should be able to get undiluted tins of similar paints from a car paint vendor, they can blend you a match to a panel, and you can brush or roller it on. Be sure to use a brush or roller that is solvent tolerant, or it will disintegrate.

For the sake of the hangar when spraying, I've suggest a temporary spray booth frame with sheet plastic.
 

Matt G.

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If you paint over it, the next layer of paint may react with it or lift it. I wouldn't chance that if I were you.

Most of those spray can paints are enamel. Acetone should take it off, but may damage your plug, depending on what it is made of. Epoxy will be fine and polyester resin should also be fine; if you used any pink or blue polyurethane foam to construct it, that will probably dissolve.

There is no reason you can't spray automotive paint with an inexpensive HVLP gun from Harbor Freight or a similar store.
 

wsimpso1

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No matter how you coat the surface, you will still have to block sand it to your finish level, then buff and wax in prep for making the mold.
 

Pops

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Krylon is a urethane enamel. I painted the SSSC with Krylon in quart cans. Rolled it on and with 25% MEK it flowed out and looked sprayed on. Sherman Williams quit selling it in quarts and now only in spray cans. I got a SW dealer to call the factory to see if I could buy the Krylon by the gallons. The answer was NO. I forgot to put an inspection ring on the fabric and tried to take the paint off with MEK, Didn't do anything, had to use a strong paint remover. Painted the SSSC with Krylon in 2006 and still looks new.
 
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I am not sure if automotive paint will go safely over what I have already on it?
If I were to bet on this I'd give pretty good odds that the rattle can paint will lift/crinkle. You have 3 options:
Test and hope.
Remove all of the paint and start over.
Spray a sealer coat designed for the 'proper' paint system you end up using. Sand through the sealer and you get to start over on that spot.

I at one time liked to roll on PPG K-200 for a primer surfacer with 4 inch foam rollers. Worked great but it is no longer available. K-36 wasn't quite as good - IMHO.
 

Kyle Boatright

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Trying to fill/smooth with paint Is a nearly futile effort. I’d scuff it then apply (squeegee on) a couple of coats of epoxy to seal it. Then use a high build primer on it. After that, sand to shape/smooth and finally paint it.
 

Pops

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Krylon is tough, I used to paint my control line planes with it and even the hottest fuels would barely touch the stuff.
IF I could buy it in cans, I would use it on every airplane. Also it does not get hard and crack on fabric. I have a test panel that I have had everyone in my hanger beat on it since 2005. Still as good as it was sprayed yesterday.
Back in 2007 when I painted the SSSC the total cost of the covering and paint was $200. 2 cross coats of brushed on silver ( have to keep it stirred ) to work it down in the weave of the fabric, and then two cross coats of rolled on and use a fine tip brush to bust any bubbles from rolling behind the roller. Will flow out and look like it was sprayed.
 

rsrguy3

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So, yes you can use auto primer with a roller. Use high build with a good amount of reducer to promote good flattening with less orange peel...
Here's the deal though, for tool making you should use something like duratech as it can be sanded through every grit then it can be polished, waxed pva'd and its ready for tool layup...
 

rsrguy3

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Oh... use a sealer coat like Nason sells, you can also roll it then use the duratech that might keep it from interacting.
 

dwalker

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Eastwood is selling a toll primer kit that would simply the OP's life a lot. I agree with rsrguy3, use a sealer coat once its smooth and the way you like it to help prevent issues.
 

rsrguy3

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I'd seal it first... then go straight to duratech. Here's the deal though once you have a good coat of it down, you absolute have to use guide coat to get it absolutely flat with 400.. then take it out of there and actually shoot at least 2 coats more of duratech. Then sand 600 through 3000 and then polish then wax with part all... about 300 times!
 

dwalker

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Hmmm I think that is backwards for aircraft. after micro and sanding to get "close enough" I would do an epoxy wipe procedure to get the parts as straight as possible with minimal trips over each part, ending with a 800 or finer surface finish. Then in this fellows case would prime with a roll primer, sand that smooth to 800 scratch again, apply a sealer, probably only one light and one wet coat at a reduced gun pressure to minimize the need to sand out peel. After the sealer I should not have to sand anything at all. All that is left then then lay down the base/clear or is using a single stage, the topcoat. I would use an airgun, probably a conventional tip over an HVLP unless he has enough compressor to do the job, but if he is like a lot of hobbyist just smoke down a couple light tack coats with a HF purple gun then reduce pressure slightly and lay down a wet coat or two. Let dry, fix the flaws, sand, polish, fly.
 
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