Painting questions, what nap roller to use? Options

[swood]

Just Kidding.

I'm cleaning out the engine bay, pretty much sanding down all the glue, removing all the dirt and wire brushing out the rust (just surface, no deep rust). The side and rear panels don't need much in the way of repair, so, can I just lightly sand them and tack cloth it to prepare it to recieve paint? I have a self etching primer for the firewall that's going on nice and smooth.

My color is Palma Green Metallic. I'm not sure if metallics are meant to be color sanded much, if at all. I guess that question is more for the exterior, the bay I'm using a single stage paint, so as long as it doesnt run I probably won't worry about the sanding.

[Slowpoke]

I hesitate to answer this. As soon as I say don't do something, someone will say I do it all the time and it works great.
I would think most painters would not recommend to top coat over an old top coat without some type of primer or jam-sol or something to open up the old paint. On an engine compartment it is important to get it as clean as possible with a strong cleanser. Then blast or brush to bare metal where there is rust. Acid etch prime where you have bare metal (it does no good over any type of coating already there). Wet sand all the old paint acid etch primer and urethane prime the entire area. Wet sand again, let it dry a day and top coat. Some people skip steps and it works great. Other people skip the same steps and it falls off in two years. YMMV
Painting is getting really expensive. It cost me also $1500 in materials for an average condition car to follow all the steps the paint people recommend. 10 years ago it was alot cheaper. But, when you have a paint problem now the paint company sends out a guy with a microscope to examine the paint and what you did or didn't do. Just not worth skipping steps, I don't think. Good luck (IMG:style_emoticons/default/smile.gif)

[Kargeek]

I’ll give you some tips on paint and painting your car. I have painted a number of cars and learned a lot of tricks the hard way. With either single stage or two stage paint, the only reason to color sand the top coat is to remove the texture in the paint called orange peel. This is caused by the spray droplets of the paint gun and how well the droplets flow together during the settling or flow out of the paint. Actually, the older style of non HVLP spray guns are better as they have a finer atomization of the paint. Newer high volume low pressure spray guns put on more paint with less air and may leave more orange peel. I have had good results with both but paint mix and proper reducer is important. If you are able to paint areas of the car like the door jambs and the engine compartment, trunk etc., without any runs and you have mixed the paint properly with the right reducer for the temperature that you are spraying – you shouldn’t have to color sand it. I still have a preference for single stage paint as I think it has more depth with solid colors than adding clear over it. An over amount of clear on a light metallic color can sometimes have a yellow cast too.

Now a tip if you are painting a complete car- trunks, jambs, engine compartment and you are planning to do the car in sections. Paint the outside areas of the car first, mask the outside and paint the trunks, engine compartment later. It’s easier to mask the outside of the car than mask the entire inside areas like jambs, inside the trunk and hood etc. Plus, you are going to color sand the outside anyway to have the perfect finish. I learned the hard way and had to go back and scrub and polish overspray off the inside areas.

Regards, Dave Hall

[swood]

Hmm, good food for thought. Thanks. I'll do some practice squirting before hand.

I have the acid etch primer but not the urethante primer. Is it that important?

[Kargeek]

Slowpoke has some good advice. Acid etch primer is for bare metal- spot prime bare metal areas with this. Go to your paint store and ask about the materials you are using. Prepairation is key for a good paint job. Also, remember that breathing vapors from the new urethane paints can make you very sick so, take precaution and have the proper resprator. DH

[thesey914]

Kageek, what kind of respirator would you recommend? I've done some research on paints and from what I've read epoxy primer is the way to go, really tough and protective and sticks to any thing.
Are the replaceable canister filters safe for isocyanides (sp?) like this ... or do you need an air-fed mask

[redshift]

I use something very similar to shoot laquers.


M

[Rusty]

You're getting some good advice, IMHO.

That respirator unit is a good one. It will keep you safe from breathing isocyanates.

When not in use, keep the cartridges sealed in a zip-lock to extend the life of the charcoal.

-Rusty (IMG:style_emoticons/default/smoke.gif)