Paint Over Trailer Powdercoat

[haulnazz15]

Hello all.

I've got a nice tandem axle trailer that came with a parts boat I bought, and I'm going to go ahead and swap it out for my existing tandem axle trailer. The new trailer (2001 Trailmaster) has a good powder coat on it with very few rust spots. However, it is a beige color and I'd like to take care of the few rust areas and paint it something like a wine-red. I've searched about every term I could, but couldn't find a thread where someone had painted over a powder coated surface, or what they used to do so.

Here's the current plan: use a wire wheel on the dozen or so spots, then wipe down with mineral spirits or similar and spray a rust-inhibiting primer on those spots to seal them. I don't know if I need to spray a full primer coat on the trailer, or if I should just go ahead with a few coats of single stage paint. Any suggestions on products or other options that would work better for adhering to the existing powder coat finish?

I intend on using a HVLP Harbor Freight gun (it doesn't have to be a showroom finish) with a 20gallon oil-less compressor. I know it isn't the best compressor, but I think it should be okay given the amount of surface area I need to cover. Compressor has an air/water separator as well.

Let me know what you guys think as I'd like to get started on this in the next week.

 

[73Chrysler105]

Re: Paint Over Trailer Powdercoat

Powder coat is nothing more than paint in powder form thats been melted on instead of vaporized on. Actually its more plastic than paint but I would scuff the entire trailer and paint it. Usually powder coat wont rust under it and does not scratch easily. Are you sure it is powder coat and not paint?

 

[NickMcCabe]

Re: Paint Over Trailer Powdercoat

Definitely gonna want to lightly hit the whole thing with the wire brush or you will have adhersion problems later. I wouldn't worry about priming all of it though.

 

[haulnazz15]

Re: Paint Over Trailer Powdercoat

The rust spots are just in a few places where the fender was scraped and around the bow post from being moved/repositioned a time or two it appears. 99% of the trailer has solid powder coat/paint, the 1% is is light surface rust from small dents/scratches. Any suggestions on type of paint/hardener and mixing ratios? From searching, most people seem to prefer an epoxy-based hardener and paint from Rustoleum or Valspar. I've never painted with an HVLP gun, so it'll be a learning curve to get the right spray pattern and such, but I'll just do several light passes to avoid getting any runs in the paint.

 

[Woodonglass]

Re: Paint Over Trailer Powdercoat

This will be helpful..

HVLP Spray Gun Setup

"Paint Your Boat for Under $100 Bucks...Well Almost"

Scuff with 220, final wipe down with acetone.
I always recommend using the recommended primer for the paint. It aids in adhesion. Your trailer...Your choice.

 

[haulnazz15]

Re: Paint Over Trailer Powdercoat

Excellent info, Woodonglass. I'm pretty mechanically inclined, but just never had much cause to venture into the automotive-paint area. A light scuffing with 180-220 ought to do just fine for prep, then srap the Magic primer and then single stage base coat.

 

[Woodonglass]

Re: Paint Over Trailer Powdercoat

Yeah, and I'd seriously consider using the Hardener. It really makes the paint hard as nails and very durable. Super Glossy too!!!!

 

[haulnazz15]

Re: Paint Over Trailer Powdercoat

I had planned on using hardener to help with the durability as well as not wanting to wait 1 week or more for the paint to cure out, lol.

 

[Streetgang]

Re: Paint Over Trailer Powdercoat

Mr. Haulin,

Not sure if this is applicable in NE OK but here in the Midwest liquid ice melter is used frequently. It has additives to make it flow and to adhere.

My point is that once bare metal is exposed this liquid will work its way under the good paint and you wont be aware until that ugly blister starts rising.

So, just as a suggestion when cleaning up the rust spots be a bit aggressive on the surrounding area to insure you get clean metal.

 

[NSBCraig]

Re: Paint Over Trailer Powdercoat

Use 80 grit on a DA not wire wheel.

 

[haulnazz15]

Re: Paint Over Trailer Powdercoat

Streetgang, that is a good point, but fortunately we don't typically get a lot of snow/ice, and the trailer doesn't leave the shop unless it's late spring, lol. If this was for a fishing rig, i'd definitely be making sure every last bit of rust was ground to shiny metal.

 

[haulnazz15]

Re: Paint Over Trailer Powdercoat

Use 80 grit on a DA not wire wheel.

Why would a wire wheel or simply a decent hand sanding not be sufficient for a few spots? Getting a DA sander seems like overkill since this isn't a full out restoration.

 

[Woodonglass]

Re: Paint Over Trailer Powdercoat

60 grit hand sanding will be just fine. Wire wheel in the crevices. Rusto Primer KILLS rust and stops it from growing so if you don't get it down to bare metal it'll still be OK.

 

[haulnazz15]

Re: Paint Over Trailer Powdercoat

Update:

Well, I've removed the bow post and fenders and washed the trailer thoroughly. I will be roughing up the paint with the hand sanding/wire wheel this coming week. I purchased the HVLP gun from HF as well as a moisture separator and a second pressure regulator/gauge to be installed at the base of the gun. I had a question on the paint type. I have looked at the Majic and Rustoleum implement paints, but I don't care for the shade of red they have available (typically a MF or Ford variant). Has anyone used the Sherwin Williams Planet Color line of paints? I can get a couple of quarts for less than $70 that just require mixing in the activator to make the full quart. I guess my question is: is 2 quarts of color coat enough to cover a boat trailer (approx 25 ft overall length)?

With this paint, I'll have to lay down a primer coat, then base and clear (for UV protection) as it's a 2-stage paint. I haven't been able to find a single-stage urethane that comes in a dark red (crimson or merlot). I also don't care to be spending $200+ on paint for a trailer than gets used a dozen times or less a year.

Side note: paint I was considering was S-W Planet Color Barrett-Jackson Collector Color Series: Spicy Merlot Pearl

 

[Woodonglass]

Re: Paint Over Trailer Powdercoat

You can use the Rustoleum and buy a half pints of various colors to add to the red to make it more of a Burgundy color if that's what you want. It's easy to do and a whole lot cheaper. I quart of paint should be plenty to do a trailer. You have to thin it so 1 quart actually yields about 1 1/2 quarts of actual paint. That should be more than enough to give you 2 good full coats of paint on the trailer. It did on mine.


How to make Burgundy Paint.

Cool: Start with a primary red color, of course. Add a small amount of primary blue (you can always add more later, but too much will make purple), and then add black until you achieve the tone or value of maroon that you desire.

Warm: Same as above, except instead of the blue you would use a small amount of primary yellow to achieve a warm maroon that will have a hint of a brown color as its base (you can not add brown itself to it, as it is not a primary color and will create mud).

 

[NSBCraig]

Re: Paint Over Trailer Powdercoat

Cause your trying to make the paint adhere to the powdercoat.