Thinning Ratio for Interlux Precote primer?

[Fletch170]

Tried finding the information.....no luck. Using the one part Poly with a gun. Primer calls for interlux 216 thinner...but how much?

Would I be better off just rolling this stuff on....assuming it's just the primer?

[slippery73]

Tried finding the information.....no luck. Using the one part Poly with a gun. Primer calls for interlux 216 thinner...but how much?

Would I be better off just rolling this stuff on....assuming it's just the primer?

Typically you thin to about 10%, usually 15% max on any coating. There isn't an easy chart to go off of, its really dependent on equipment, operator, and weather conditions.  Personally, I don't like to thin anything unless I have to.  Thinning paints is effectively ruining the quality of the item, expensive paints have higher solids content. Thinning out a coating is just adding in more material to evaporate.

I usually only reduce in the summer time when Its hot and the coating is curing to fast, then I add retarder.  Its a must when spraying large pieces to be able to maintain a wet edge.

The right equipment will solve almost any issue regarding thinning.  If Im spraying with my hvlp guns, I have tips ranging from 1.3mm to 2.2mm. This covers a large range of viscosities, I generally use 1.8mm to 2.2mm tips.  My technique is pretty fast though, if your just learning and you spray slower, a smaller tip may help. Do some test pieces, see if you get sags or runs. Speed up or slow down accordingly.  You want to wet out the surface enough that the spray particles will bridge and smooth over, to light a spray and you have a rough texture, to heavy and you will get runs.

You will need to adjust your gun properly,  adjust the fan so it has a decent spray width.  You will want to adjust the air pressure as well, to much air and you will over atomize causing bounce back and a lot of wasted material, to low of air pressure and it won't smooth out without really laying it on heavy.  Most beginners go way overboard on the air pressure, start low and turn up accordingly.  

For really thick coatings we use an airless sprayer, we've shot some euro waterborne coatings that were the consistency of jello. A good starter hvlp gun with multiple tip setups is the devilbiss finish line gun.  Best bang for the buck in my opinion for an entry level gun.  

If your going to spray, INVEST IN A decent HVLP GUN.  Hobbyist seem to cheap out on this yet try to spray coatings that cost, $100 a gallon.  HVLP transfer efficiency = 50-70%.   Conventional spray guns =20-40% efficiency.    That means for a good gun half of your material is trash, for a junk gun... figure 75% of your sprayed material is trash, floating in the air. A good gun with a high transfer efficiency will pay for itself really quick if your spraying costly materials.

[Fletch170]

Hahahaha, ahhhhhh crap. I thinned it out wayyyyyy too much. I got the pressure at 50 psi, where interlux suggested. Really good advice though, thank you so much.

[slippery73]

Turn your pressure way down, especially now that its thinned.  You'll want to spray thin coats to prevent runs, first coat should be a mist coat. Let the mist coat kick then go into additional coats, the first coat will help the following coats grab without running.

[Fletch170]

I have it at 50 psi, that is too high?

Just a sanity check, I want to be about a foot away, always shooting at a 90 degree, sand between coats, clean. Right?

Should have the pattern looking like an oval.

Where can I get an air cleaner?

[slvrlng]

Which spray gun do you have? They all have a different demand for air and fluid. That entails reducing the coating to where the gun will spray it correctly. Never ever test the pattern on what you are going to spray always spray on something you don't care about, but you will be able to see the results. How much have you reduced it already?

[Fletch170]

Yeaaaaa, I'm dumb and thinned it out 3:1. It was like watery milk.

Hey, I'm learning!

[Unclebob]

Just curious. If you're priming, and taking it off by sanding, then why are you spraying instead of just rolling?

[Fletch170]

Unclebob,

I asked the same question earlier in the thread. I guess I'm doing it as a way to learn how to use my spray gun.

-Fletch

[slippery73]

I have it at 50 psi, that is too high?

Just a sanity check, I want to be about a foot away, always shooting at a 90 degree, sand between coats, clean. Right?

Should have the pattern looking like an oval.

Where can I get an air cleaner?

A foot away is kind of far, probably losing a lot of material like that.  Each gun will spray different, I dial my guns to spray an 8" fan that is  1.5" wide. It looks like a big hotdog.  You will want to try to get your gun as close to that as possible.  An oval pattern will give you poor overlap.  

As far as an air cleaner goes, you need a good filter and you need to get rid of moisture. The filter is easy.  The key with removing moisture is not letting the air get hot enough to condense, or.... control where the air condenses in the lines so it can be removed.