[jcclark]

I know that all clears are a different viscosity but do any
of you guys get by without any reduction? I usually add
about as much thinner as I do hardener. It would seem
to me that the less thinner the better (less dye-back)
But it doesn't spray very well if its thicker so what's
the goal here? A bigger tip on the gun? Or more thinner
and longer waiting between coats? I know some of you
are goin to say follow the mfg, but some don't really
tie it down. Do you have a viscosity rating you gage against
like a "Ford" cup. If you do let me know how much you like.
I think I go about 15 to 20 seconds.

[BarryK]

15 seconds is really to thin. Stay around 20.
Its always best to have proper gun adjustment so you don't need to add reducer to a clear that does not require its use for mil
build up if nothing else.
Reducing like you are 4:1:1 if your using a medium solids clear
you will need 3-4 coats to achieve your 2 mils of clear minimum after you are done wet-sanding and buffing.

A lot of painters will add 1-4oz per mixed quart of clear on their last coat and that don't hurt a thing.

Also be concerned about the type of urethane reducer you are using as the cheaper ones will have a higher amount of water content say in the area of 6000-10,000 parts per million.
A good one such as DT870 or BASF BR-60 or Dupont will have 500-1000 parts. Water does cause havoc with the isocyanate's.

[mrcleanr6]

not to get off subject here but barry, you brought something up that i have been wondering about for a while. the water content in reducer.... i think i have read on this forum and have been told by one of my suppliers a year or two ago that all the urethane reducers in the US come from only 3 different chemical suppliers. if thats so, why would there really be any difference in water content unless it has been added after it has been recieved at the paint companies. another thing, i dont reduce my clear but are there any drawbacks if a cheap reducer is used in basecoat and primer assuming there is plenty flash time??

[jcclark]

Thanks Barry.
4 coats is my usual amount. I use Sherwin Williams Ultrasolve
thinner. (it's a universal thinner)
Even though I switched 2 yrs ago to Dupont Base for colors
I've stayed with the same thinner for all my clears.
I really like the S/W brand, it comes in several different temps
and because I have all of them I've stayed with it.
They have one that is desert rated. (95 degree and above).
I use a little of that for bumpers and stuff I don't want to
rub out. It just lies there wet (without a lot of thinning)
and really melts in all over to a great finish. (watch out for dirt!)
Do you ever add a little retarder to the last coat of clear?
I've heard mixed opinions on retarder but it helped
me a lot when I used acrylic enamel.
I also spray cabinets with furniture lacquer and couldn't
spray without it.
But I'd like to hear more on retarded with clear.
Any drawbacks or cautions?

[BarryK]

There is one key chemical supplier that will make urethane reducer to your formula and most of us use them.
Its actually cheaper this way because they are so efficient.
Your medium urethane reducer arrives in the size tote of your choice and you can it from there.

So in a round about non getting hung way, let say you are a big company with two brands (different names) you would have two formulas. Getting rid of the water is costly.

Re: Cheap reducer in base or primer.
Primer it would be worse than base unless you are activating your base.
Base you may see blushing if not activating.

The type of quailty paint work you do, I would never take that gamble!

Originally posted by jcclark
Thanks Barry.
4 coats is my usual amount. I use Sherwin Williams Ultrasolve
thinner. (it's a universal thinner)
Even though I switched 2 yrs ago to Dupont Base for colors
I've stayed with the same thinner for all my clears.
I really like the S/W brand, it comes in several different temps
and because I have all of them I've stayed with it.
They have one that is desert rated. (95 degree and above).
I use a little of that for bumpers and stuff I don't want to
rub out. It just lies there wet (without a lot of thinning)
and really melts in all over to a great finish. (watch out for dirt!)
Do you ever add a little retarder to the last coat of clear?
I've heard mixed opinions on retarder but it helped
me a lot when I used acrylic enamel.
I also spray cabinets with furniture lacquer and couldn't
spray without it.
But I'd like to hear more on retarded with clear.
Any drawbacks or cautions?

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

You do know you cannot use the ultra-solve in your Dupont base!!!! Very Important.

The S&W Reducer is a great one.
Retarder use in last coat only to be safe. Your slower reducers have enough MEK in them you don't need retarder.
Some retarders are not as slow as the very slow urethanes reducers and made so many different ways its just too much of a risk. If you found one that works don't change brands!

[mrcleanr6]

ok, i think i understand you. the reducer arrives at the paint compaines in sort of a raw form and its really up to the paint compaines to remove the water from it?? i always used rm or hok reducer and was very hesitant to try something else so i ordered a gallon just to try it out. that was 2 years ago and i have never had a problem with the stuff. actually i never saw any difference at all when i switched over. i think i pay around $40 for a 5 gal pail and its made by ppc if that means anything to you.

[BarryK]

NO:

It arrives at the paint company mixed to your formula, already done. But did you order the cheap industrial grades or the good ones?
As i understand it, they get a tanker car in of one chemical and as much as 10 % may be water. So since water separates its divided up into industrial grade and urethane grade.

[mrcleanr6]

ok, i got it now.....thanks

[jcclark]

Barry: No I would never use the thinner for the base, I have cheated by using S/W base reducer in the Dupont base.
They both have the same ingredients and it worked fine
but the clear reducer I only use in clear and primer.
(it's expensive though, aronf $30.00 a gallon)
But I use such a little bit it goes a long way.
Thanks Barry, I'll try and get another question later
that'll make everyone think. I'm good at doing that.

[BarryK]

Barry: No I would never use the thinner for the base, I have cheated by using S/W base reducer in the Dupont base.

Never do that! They are not the same, Dupont has a hidden bomb in theirs for that very reason. Clear peeling problems down the road. DON'T do it.

[jcclark]

Ok, thanks. I also never use the same brand clear over
the base, do you have a problem with that?

[BarryK]

Not a problem.
Just the base blender is.