Thinning oil-based paint before painting metal

[zruvalcaba]

I'm about ready to begin painting all of the parts on my Clausing DP resto. I properly stripped all of the parts of their original paint, blasted them in my cabinet, and have applied Rust'O'Leum white primer to all of the parts. Here's where I'm at so far:

https://dl-web.dropbox.com/get/Public/Photo Dec 31, 12 07 40 PM.jpg?w=68e70994
https://dl-web.dropbox.com/get/Public/Photo Dec 31, 12 07 28 PM.jpg?w=598e6a6a

The primer went on super smooth...no problems. However, I used the same brand paint to paint my new workbench frame and I was less than impressed with the results of either the paint or the spray gun. I tried adding a bit of mineral spirits to the paint but it didn't seem to help. My question is, how much (if any) mineral spirits should I be adding to thin the paint?

I paint my guns using KG GunKote 2401 Black and the consistency of this stuff is like water. I use a HVLP detail gun and it works amazing. Using a more industrial HVLP spray gun for the DP but I want to make sure the paint goes on nice and smooth with no globs or spatter on the parts....this is what i got on some parts of my workbench frame. Really would like to avoid that on my Clausing DP. Thanks for any advice.

 

[FrankieD]

I believe the Rust'O'Leum label says to use xylol or xylene to thin their paints for spraying.Hope this helps.

 

[e-tek]

READ THE DIRECTIONS!

For most of thuse tpes of paints, Minimum thin is 10%, upt to 50%.
Before you paint your parts, paint something else to check everything.
Never practice on your final piece!

 

[rlitman]

They often now say to thin with acetone if spraying. That's because of VOC regulations.
Acetone will "flash" faster than xylene, and can be more difficult, so xylene may be your best bet (even if it doesn't explicitly say that in the instructions).
A little mineral spirits (emphasis on little) is ok for a brush finish with most rustoleum paints (just not the hammertone or metalic ones, don't mess with those).

 

[slip knot]

Been a few years since I painted anything with a paint gun but we always used "enamel reducer". You could get it in different speeds for hot or cold temps. Don't know if this stuff is still pertinant with the hvlp paint sysytems. Acetone always flashed too fast for me the surface never would flow togther.

 

[mike13u]

Should say exactly what to do on the can. Dont worry, its not like asking for directions, reading a paint can is not against Man Laws.

 

[zruvalcaba]

Should say exactly what to do on the can. Dont worry, its not like asking for directions, reading a paint can is not against Man Laws.

Guys, I DID read the label. It specifically states to use Mineral Spirits or Acetone to thin the paint. My question is how much? I used Mineral Spirits on my last job and it didn't exactly turn out smooth. I had spatter....

 

[mike13u]

I would start at about 30% mineral spirits and move up if necessary. I dont have any experience with that particular paint though. Is it an enamel? Thats what I have used for machines like my mill. If its an enamel, will you be useing a hardner? As others have said, its sometimes trial and error. Test on soem other items first. I would start in the 20-30% and work up if necessary .

Good luck and post pics of the finished drill press.

 

[sberry]

Just enough to make it spray well, usually around 10%, if it wont go thru gun obviously its too thick.

 

[uhohjim]

I thinned out my Rustoleum about 10% with mineral spirits to spray my garage door.........Came out awesome nice gloss and no problems..........also read on here somewhere that a guy was using enamel hardener in his Rustoleum and he ended up with a super hard super glossy finish.......I'll be trying that on my bandsaw rebuild........Jim

 

[MoonRise]

RTFM for the product and RTFM for the tool.

You say the paint can says to thin with mineral spirits or acetone. But it didn't say how much to thin by if spraying? Most of the paint cans I've seen/used list not only the thinner to use but also the rough amounts (such as: thin no more than 10%, etc, etc).

If you don't understand the label, you can almost always check the maker's website or <gasp!> call their Tech line. Most makers want to help make sure you get 'good' results with their products.

And related to RTFM for the product, you also have to RTFM for the tool/device you are using with the product.

Saying 'spray gun' isn't quite enough if you want a detailed answer as to thinning amounts.

Tiny little 'artist' type airbrush with the smallest needle and tip? Honking mondo-sized HVLP 'production' spray gun? An airless 'spray gun' with a small diameter tip or a large diameter tip?

All can be used to 'spray paint', but not all can be used to spray all paint.

That's why you have to read the tool manual, and see what it says/recommends as far as sprayable viscosity for the paints that it says that sprayer can spray.

 

[rlitman]

Guys, I DID read the label. It specifically states to use Mineral Spirits or Acetone to thin the paint. My question is how much? I used Mineral Spirits on my last job and it didn't exactly turn out smooth. I had spatter....

Indeed it does, but only on NEW cans. Oh, and did you notice that the can doesn't have the word "paint"?
Cans I have had sitting around for years say to thin with xylene.

It's all about government regulations. Seriously!

Oil based "paints" are no longer legal in the US, because of their VOC content. Now, they're a "rust preventative finish", or "wood finish", or "stain", or something else along those lines.

Old cans said to thin with xylene, not any more. The paint formulation has not changed, BUT the VOC regulations have. Nowadays, the government is more strict about "aromatic" VOCs than "aliphatic" VOCs. Xylene is aromatic. Acetone and mineral spirits are not (ok, enough with the chemistry lesson).
If the manufacturer recommended to thin with xylene, the thinned product would not be legal to sell, so they were forced to change their recommendations to a less suitable alternative.

 

[zruvalcaba]

Gotcha, thanks for the detailed information. So where can Xylene be found? How much should I add...10%? As for a hardener...should I add this as well?

 

[sberry]

Hardener can make it shine and dry quickly but,,,also makes it more toxic. This is a piece of equipment, stored inside, doesn't need the durability of a truck or airplane. Won't even fade in the sunlight. I sometimes paint some pieces with common spray cans, looks good for a long time indoors.

 

[uhohjim]

I didn't use a hardener and got a nice shiny finish that is still in good shape after a couple years out in the elements. That said I'll be trying some enamel hardener with the Rustoleum on my bandsaw project when I paint it.You don't need the hardener the rustoleum will dry pretty quick when sprayed...............I did use a cheapo Harbor Freight gun when I shot mine rather than taking a chance with fisheyes later on down the road from using oil based paint in the gun....But again the finish came out awesome.........Jim

 

[zruvalcaba]

I'm using a HF spray gun as well. I suppose I'll just give it a shot and see how it turns out.

 

[rlitman]

So where can Xylene be found?

Right next to the acetone, denatured alcohol and mineral spirits in the aisle of most places that sell paint. At least, that's where it always is in the orange or blue box stores.

 

[trbomax]

I always used lacquer thinner, dtl10 ditzler to be exact. Its a med speed thinner for color,not clear. For rustoleum and similar alkid enamels about 10% to start with,the keep adding it a little at a time untill your spray outs are what you want. The dtl10 will allow good flow out along with a medium flash speed,thus eliminateing runs if you paint "wet" These paints flow much better and develop better gloss if "smoothie" is added at 150% recomended dose. I have been useing an accuspray hvlp gun for about 20 yrs doing this.

 

[NUTTSGT]

I used mineral spirits to thin Rustoleum when I painted my walk in garage door this fall. I've used it before this project.

 

[uhcrandy]

I used my devilbliss primer gum to spray my outdoor metal furniture. I used rust-olium, in the gallon. I used acitone to thin it. I used more acitone than I thought i should. In hind-sight I may use even more next time. I seem to have got a better job with more thinning.

 

[gadgetman333]

Im sure you finished your project 12 years ago by now but I still want to address all the bad information on here just in case somebody stumbles across here looking for advice. I used to work in a body shop...... when thinning painta for spraying you need to use a viscosity gauge, theyre super cheap and super simple little devices. The specific viscosity should be set according to what is recommended by your spray gun manufacturer and should be specified in the owners manual. If it isnt then you must have bought a cheap chincy spray gun and your finish is never going to look right anyways so blast away cuz my advice wont help you one bit. As for the proper solvent to use as your thinner you want to go with whatever the manufacturer recommends. Each paint has a specific Material Safety Data Sheet created by the manufacturer as required by law that will list every component used to manufacturer their paint and should also have information that specifies what additives can safely be added to their paint. Dont just start dumping reducer, hardener, dryer, etc in your paint because it can ruin the structure of the paint causing the components to seperate and a manufacturer can make what appears to be 2 similar paints of different colors but actually consist of entirely different components. Quite frankly you havent provided enough information about the paint you are using for anyone to offer you any useful professional advise so you should disregard any thats been offered. The best thing to do is go to a paint specialty store (that doesnt mean the home depot paint counter) and talk to the guys behind the counter because nobody knows their paint better than they do and theyll set you up for success..... as for your splatter that could have been a number of things including not having the gun calibrated properly. Im assuming that if you didnt know to test fire your gun on a piece of cardboard so you could dial it in before spraying your project then it is likely you werent familiar enough with your gun to dial it in properly...... my guess is you had the air pressure set way over 15- 20 psi, which should be roughly about where it should be set when laying down a basecoat but thats also something the guys in the paintshop can help you work out. They get that stuff all the time so dont worry about feeling stupid for asking stupid questions. What makes you look stupid is blasting paint everywhere when you could have just asked these guys for their free expert advise that they are more than happy to offer you.

 

[Hellpig]

Im sure you finished your project 12 years ago by now but I still want to address all the bad information on here just in case somebody stumbles across here looking for advice. I used to work in a body shop...... when thinning painta for spraying you need to use a viscosity gauge, theyre super cheap and super simple little devices. The specific viscosity should be set according to what is recommended by your spray gun manufacturer and should be specified in the owners manual. If it isnt then you must have bought a cheap chincy spray gun and your finish is never going to look right anyways so blast away cuz my advice wont help you one bit. As for the proper solvent to use as your thinner you want to go with whatever the manufacturer recommends. Each paint has a specific Material Safety Data Sheet created by the manufacturer as required by law that will list every component used to manufacturer their paint and should also have information that specifies what additives can safely be added to their paint. Dont just start dumping reducer, hardener, dryer, etc in your paint because it can ruin the structure of the paint causing the components to seperate and a manufacturer can make what appears to be 2 similar paints of different colors but actually consist of entirely different components. Quite frankly you havent provided enough information about the paint you are using for anyone to offer you any useful professional advise so you should disregard any thats been offered. The best thing to do is go to a paint specialty store (that doesnt mean the home depot paint counter) and talk to the guys behind the counter because nobody knows their paint better than they do and theyll set you up for success..... as for your splatter that could have been a number of things including not having the gun calibrated properly. Im assuming that if you didnt know to test fire your gun on a piece of cardboard so you could dial it in before spraying your project then it is likely you werent familiar enough with your gun to dial it in properly...... my guess is you had the air pressure set way over 15- 20 psi, which should be roughly about where it should be set when laying down a basecoat but thats also something the guys in the paintshop can help you work out. They get that stuff all the time so dont worry about feeling stupid for asking stupid questions. What makes you look stupid is blasting paint everywhere when you could have just asked these guys for their free expert advise that they are more than happy to offer you.

Wow!
Just, WOW.

 

[PCustoms]

Wow!
Just, WOW.

New guy coming in a little condescending 12yrs later. I might have read it if it had paragraphs

 

[NUTTSGT]

New guy coming in a little condescending 12yrs later. I might have read it if it had paragraphs

I read it and he needs to find another forum to bash his fellow members.

That's not how we operate here. Decade plus old thread closed.