Rustoleum thinning ratios

[PlayD0h]

so I have 1 coat of paint on, using the rusto topside and it didn’t atomize all that great. I used rusto’s directions and mixed 15% xylene, yet there are a few other ratios reccomended which call for more acetone/xylene. I just read that acetone is recommended for lower temps, xylene for higher, so I’ll use acetone next time.
My gun sprayed primer good with the same setup, 1.4 tip hvlp gravity fed. My only theory is that the paint was at 55-59°, and that bringing the can in the house to warm up before spraying might resolve the problem.
I really want to follow rusto’s ratios, yet I wonder why a lot of people use other ratios? I’ve seen people say a 1:1 works good, but I can’t imagine that gets much paint on.
I was planning on using valspar hardener, yet now I’m leary, since rusto apparently doesn’t recommend it. From what I’ve learned is that hardener chemically cures the paint, and the only real ‘benefit’ is a quicker cure time which somehow makes the finish more shiny. If I have time to wait, is it better to skip the hardener? Does it actually make the paint more durable?
my plan is to paint and let it sit for 2 weeks or so before flipping it upright and trailering it. At 55° average is more time better?

 

[zool]

You can thin Alkyds like Rusto up to 25-30% if needed, I usually do 20+- with Acetone and/or mineral spirits, plus the hardener.and do one dry coat and 2 wet coats. The hardener will help with durability, but its not needed to cure.

If youre having trouble atomizing, increase the air pressure a bit.

 

[Woodonglass]

I've used Rustoleum a LOT. Trying to shoot paint at temps below 70 is always a struggle. Not only does the paint need to be at that temp but the substrate you're painting does to. I'd highly recommend getting the boat into a heated atmosphere and then use Acetone You can go as high as 30% . the Hardener IS highly recommended not only for the reduced drying time but it also greatly enhances the hardness and durability of the paint. Set your gun to 35-40 PSI with the regulator at the end of the gun NOT at the compressor. Multiple Thin coats IS the best way so don't worry so much about the viscosity.


This might be of interest...


Paint Your Boat with Tractor Paint

...Say What!!!​

 

[PlayD0h]

So I left my heaters on for a couple hours and got it up to around 65 F or 18°C. I put one space heater under the turtled hull to get the aluminum warmer, yet I didn’t check what temp it got to. Felt decent though.

I used your (WOG) mixing ratios and sprayed the second coat with the hardener. It just flew out compared to the 15% xylene thinning. I got a second gun, that had issues, so I had to switch, which wasted a bit of paint, but I used a LOT.

I used the whole quart on the one wet coat of the hull bottom. I used 3/4 a quart on the first coat, and figured I’d use less on the second. It looks great, and there are zero runs or sags. My only experience shooting paint was at a place I used to work, painting heavy duty equipment. So my idea of a coat is obviously not what most consider a coat.

So, I don’t think I need another coat, yet if I didn’t have this site or others as reference I would have just though my coats were normal. In fact if I can’t see how it would have looked as good if I didn’t put as wet a coat. Maybe with multiple thin coats it doesn’t look smooth until the last coat?

anyways I’ll try the thin coat method on the hull sides when I get there. Yet I wonder if there’s any difference considering there’s no runs or sags? I wish I had a paint thickness meter. I’ll see if a body shop will check it for me in the spring.

 

[zool]

Rustoleum actually gets weaker if its applied too thick, or too many coats, If its not bleeding thru, and the color looks like u want it, youre good to go

 

[PlayD0h]

Rustoleum actually gets weaker if its applied too thick, or too many coats, If its not bleeding thru, and the color looks like u want it, youre good to go

That may be true for most paints, being too thick. At that place I worked they were putting the paint on too thick and they had to buy a paint thickness meter to know how much was enough.

I guess all I can do is hope I didn’t over do it. Since it didn’t run, sag or even appear to be a too thick of a coat, I think it’s ok. When I scuff sanded the first coat I hit primer on quite a few rivets and lots of small spots that were nubs/ lumps.

 

[zool]

It is true with most paints, but especially with Rustoleum and the like, because they are air cured, and take a while to fully set up, or u risk making a jelly bean

A body shops mil thickness test would be for solvent cured, which flash alot quicker, so it may not help....

 

[Woodonglass]

Try adjusting the paint volume on the gun and you'll get less paint and better atomization. It takes a bit of practice (I spray cardboard) to figure out the gun settings for each particular mix ratio. Once you get it the paint goes down fairly nice.

 

[PlayD0h]

Here’s some pics

 

[PlayD0h]

According to the spec sheet coverage is 100ft2 per quart. And my hull bottom is close to that.

 

[Woodonglass]

Yeah, I'd say it's looking pretty good.