Rustoleum Reduction

[Wishin4a416 2,191]

For you fellows using rustoleum, what is your favored reducer and mixing formula?

I have read acetone, laquer thinner, mineral spirits, naptha, and urethane reducer but dont know which way to go.

I will be using Valspar Hardener and HP gun.

 

Now using laquer thinner to reduce enamel just baffles me. I remember years ago when spraying cars, you didnt want to spray laquer any where near fresh enamel or it would lift. And reducing enamel with LT would just make it curdle. I dont know what changed.

The guys on a car forum I check out are doing it though with good results on frames and suspension componets.

Edited February 24, 2013 by Wishin4a416

[rmaynard 15,407]

If you are talking about Rustoleum Stops Rust in quart cans, the technical data sheet says the following: For air spray, thin up to 15% with Acetone.

As far as a hardener, I would consult with Rustoleum's customer service. Valspar's hardener may not be compatible.

[Save Old Iron 1,566]

Reducing enamel is done more for the sake of complete atomization thru a standard spray gun nozzle than any chemical reaction requirement.

 

Before I would over- reduce an enamel, I would try a larger tip on the HVLP gun. Trying  to spray a thicker enamel thru a sub 1.4mm spray tip requires reduction of the enamel to almost a water like consistency. I thought a 1.1mm detail gun would be a good addition to my gun collection - NOT. Over reduction of enamels will typically promote runs and drips and lack of gloss due to over reduction. Remember, reduction is less color / more diluent.

 

I have an HVLP gun with a 1.8mm tip and requires very little dilution with reducer or solvent. I also invested in a 2.5mm gun this winter to spray metal flake on the bassboat this summer. Larger tips require a stout compressor to achieve good atomization and prevent orange peel effects.I'm going to experiment with the 2.5mm this summer on the cubs to see if I can get yellow to look better with less layers of base coat. 

 

You can reduce enamel with lacquer thinner - it works. But what you have done is add another unknown into the drying equation. The lacquer thinner will carry the enamel to the sheet metal but then you have to wait for the lacquer to evaporate to allow the enamel to begin to cure - remember - lacquer dries by evaporation of the solvent - enamels dry by chemical "curing" of the pigment and carrier when exposed to oxygen in the air.

 

Do not spray lacquer thinner over dried enamel. the lacquer thinner will lift a dried enamel topcoat. Used as a solvent to get the enamel onto the tractor - it does work.

 

Maximum dilution %'s are more related to remaining compliant with current VOC environmental laws  than performance issues with the paint. But again, over-dilution of the basecoat has it's drawbacks.

Speaking with the manufacture's tech reps may be useless as all tech reps these days are under strict rules not to deviate from the company's IFU's (instructions for use). I can attest to that from personal experience. If the company records your incoming call for "quality control purposes", a recommendation to use the product in an "off label" fashion could potentially be an EPA or FDA violation. Welcome to the new world rules.

[Save Old Iron 1,566]

p.s

 

regarding the whole acetone, naphtha, mineral spirits, toluene issue,

 

more than anything else represents a difference in how quickly the solvent will dry, Acetone is very "fast" to dry. Mineral spirits is "slow".

 

drop some acetone next to mineral spirits on a piece of metal and watch the difference in evap rates. The longer you allow the basecoat to remain wet, the smoother the finish will be - but - the more susceptible the basecoat is to runs or drips. If the solvent dries too quickly , the basecoat will be grainy, having partially dried in the air between the gun and the metal you are spraying it on.

 

Sorry for the long wind, but the more you understand from a thorough explanation, the more you can be assured of achieving good results from your initial attempt. Trust me, there is a great amount of experimentation involved in getting a process "just right". Strive for a workable balance you can live with.

[Wishin4a416 2,191]

^{Thanks guys. It will be awhile before I do the sheet metal so I'll have to make a decision.}

[rmaynard 15,407]

When it comes to paint, I think that the manufacturer has a little more experience and therefore a lot more credibility. If the technical data sheet is not good enough for you, then good luck. If you want to experiment with increasing tip sizes and using product not recommend by the manufacturer, that is your prerogative. But for me, if the TDS says to use a particular product and tip size, I'm sure that many hours of testing has gone into their recommendation, and that is what I am going to follow.