DIY Painting Tips

[Langanobob]

Thanks DP. I'll let you know how it turns out. 

Well, the tank has been sitting for a few years and the old inside coating just flaked off on its own.  I think I just have to rattle a handful of sheet metal screws around inside for awhile to get rid of it.

A new question.  I'm re-painting this tank the original color and I figured I'd just clean it up, sand and paint, but...it turns out I had to sand down to the metal in places to get rid of scratches.  My original plan was no primer.  Since I have a patch or two of bare steel, maybe 2" by 2".  I'm using single stage two part urethane (as opposed to two stage clear coat) and I *think* it will probably bond good enough to the small bare steel spots, but sometimes "probably" doesn't work so good.

Do I need to primer the tank before painting? Can I just primer the bare steel areas?  Or no primer needed?

Thanks,

Bob

[ducpainter]

You need to prime it...for several reasons. I can list them if you'd like.

If the rest of the finish has been sanded without cut throughs, spot prime and sand those areas after the primer has dried. Don't be bashful with the primer. You need to bring those areas back up to the same thickness as the surrounding paint or you'll see 'bullseyes' in the finished product.

Try to pick a primer close to the color of the tank. It will reduce the amount of paint required to cover the two different colors. That's one reason to use sealer. It gives a uniform color.

[kopfjäger]

[Langanobob]

DP, I just painted a frame and it came out OK.  I used an HVLP gun and I adjusted it the same way I adjust it for painting larger area like fuel tanks or panels since that is the only way I know how to adjust it.  For frame painting  do you use a small touch up gun or adjust a larger gun for a small pattern?  I didn't have any trouble getting a full wet coat with the full size gun but  a lot of paint missed the target.

I see that there is a  comment from the Peanut Gallery 
I know that you don't want this thread to be a sticky but do you want it to just go away altogether? 

[ducpainter]

DP, I just painted a frame and it came out OK.  I used an HVLP gun and I adjusted it the same way I adjust it for painting larger area like fuel tanks or panels since that is the only way I know how to adjust it.  For frame painting  do you use a small touch up gun or adjust a larger gun for a small pattern?  I didn't have any trouble getting a full wet coat with the full size gun but  a lot of paint missed the target.

I see that there is a  comment from the Peanut Gallery 
I know that you don't want this thread to be a sticky but do you want it to just go away altogether? 

I'd likely use my Sata Mini4. It's easier to get into places. As far as a lot of paint missing the tubes...it's inevitable. It takes six passes to get even coverage.

I don't want this to go away.
I still enjoy sharing what I know. Daryl was just referring to me retiring from active painting. I still do the very occasional favor, but I've pretty much hung up the guns.

[koko64]

 

[Langanobob]

I'd likely use my Sata Mini4. It's easier to get into places. As far as a lot of paint missing the tubes...it's inevitable. It takes six passes to get even coverage.

I don't want this to go away.
I still enjoy sharing what I know. Daryl was just referring to me retiring from active painting. I still do the very occasional favor, but I've pretty much hung up the guns.

I don't pay enough attention to what goes on around here, didn't know you hung them up.  What are you doing with all your "spare" (ha) time now?   Not always easy to stop something you've done all your life.

[ducpainter]

Well...the paint companies decided that they wanted all of the money I generated. It became impossible to absorb the increase in materials cost on most jobs. The cost for materials was higher than what I could charge.

I'm getting pretty used to my new 'job'.

[ducpainter]

I've been asked to make this thread a sticky many times, but never did because of the conflict with my business.

Now that I'm out of business, I'm going to sticky it. if it doesn't generate much activity I'll likely unsticky it so it doesn't clutter up the top of the page.

[Langanobob]

I have an air pressure question.  When I first got a HVLP gun, a gravity feed type of unmentionable manufacture, I of course read the instructions.  As I recall they said something a out the gun being designed for 10psi air pressure.  I found out later that what I read and what they meant weren't the same thing.  I adjusted the regulator on the handle for 10 psi and it turns out that they meant 10 psi at the nozzle, which translates to about 40 psi at the regulator, where I'd adjusted it to 10 psi.

I sprayed a fairing and the paint came out of the gun in a fine mist. Probably would've laid down the paint too slowly for a truck or commercial work but for an amateur hacker I think slower is better.  The end result was an OK job.  No orange peel and only one small sag.  I've read conflicting info that the paint won't properly atomize if the air pressure is too low and that seems to make sense but this paint atomized just fine.

So, having said all that I'm not sure what my question is.  Any reason, other than somewhat  slow painting, not to adjust the air pressure down lower than recommended, as long as it's getting good atomization?

[ducpainter]

As the material solid percentage goes up, the atomization quality will go down with lower pressure.

You got lucky with whatever it was you were spraying.

Keep in mind the instructions, and subsequent pressure recommendations, are a generalization based on regulatory concerns. That is, after all, why we have HVLP equipment in the first place. The secondary reason is material cost. In the backyard, it's whatever works.

[CookieMonster]

any suggestions for this

[ducpainter]

Is that OEM?

Poke a hole in it with a needle. Try to work the bubble down from the edges towards the hole. A quick touch up with some white paint, if the hole shows, and some clear.

It will only be "better"...you will likely always be able to see it, so it will never be "perfect".

[CookieMonster]

Is that OEM?

Poke a hole in it with a needle. Try to work the bubble down from the edges towards the hole. A quick touch up with some white paint, if the hole shows, and some clear.

It will only be "better"...you will likely always be able to see it, so it will never be "perfect".

yeah OEM dunno why it did that

[ducpainter]

Has the tank expanded?