Paint Touch Up - Won't Harden~!!

[goldgunner]

I'm using the techniques posted elsewhere: very light coats with a toothpick or an ultra tiny brush on chipped areas, filling slowly and waiting patiently...

I'm using paint (non-epoxy) from the same lot that the paint shop used to do my car, pre-clear coat. And yup, stirred the paint well.

Problem is my thin coats aren't drying hard - even after 4, 5 or 6 days. Yea it's been pretty humid here, but not extreme; it's been hot: + 100 almost every day for the last several weeks. The touch up spots are not tacky, but they are pretty darn soft.

Any clues as to what is happening or why it's not happening?
What to do?

Just clear coat over it and wait?

thanks,
Jim

[Early_S_Man]

What brand and line of paint is it? Are you using a reducer or thinner appropriate for the temperature?

[goldgunner]

Brand is BASF.
It's a urethane.

At first, to get it thinner to where I could do very light touch ups, I thinned it with thinner I purchased from Paint Scratch. Woudn't harden after days, so then I tried the straight paint - same result.

Any ideas Warren?

thanks,
jim

[Early_S_Man]

Jim,

I am not familiar with BASF paint, but the other common brands I have used ... Dupont & PPG, specifically, require that the catalyst which is a SERIOUS POISONOUS compound called Isocyanate [recall Union Carbide disaster in Bhopal, India] be mixed with it in order to harden properly.

I would not personally attempt to, or suggest the use of catalyzed urethane at home, because any clothing you are wearing when using it will be a serious risk of danger to anyone around due to fumes clinging to the fabric ... until the urethane is fully cured hours later! We are talking about serious, permanent pulmonary damage, as well as secondary effects to liver and other organs ... with even light exposures!

[jester911]

I had the same type of paint in a single stage. It needed a hardener with it to set up. You might need to call the paint shop you bought it from to see if it also needs a hardener.

[goldgunner]

Warren - with that important information I've searched and found:
BASF urethane catalyst tech data:
http://www.basf.com/businesses/chemicals/amines/pdfs/18-diaz.pdf

And a MSDS for that same chemical composition:
http://www.sciencelab.com/xMSDS-1_8_Diazabicyclo_5_4_0_undec_7_ene-9923705

Doesn't sound quite as bad as the Bhopal Blues...but still nasty enough to have some concerns about.

But, lacking any other solution I think I'll have to try some catalyst under my best controlled process fashion.

Further thoughts?

Jim

[ruf-porsche]

Originally posted by goldgunner

Further thoughts?

Jim

Find a Detail Shop that does paint chip work and let them do it.

[goldgunner]

Nah...I reckon there's more chips coming my way - best to just have a process I can do as needed. Besides, where's the Pelican spirit in running to a detail shop?

[RFR]

Jim,
There is the possibility that the "Skin", (the top layer) is dry and prventing or slowing the solvents underneath from escaping resulting in the softness.

Myself, Being a guitar builder by trade, encounter this with lacquer every so often.

The solution is to sand the top layer with 400 grit (wet).
This does 2 things, a) it cuts though the top layer letting the inside dry, and b) serves the purpose of leveling and smoothing.

It does solve the problem of the drying issue.


cheers,
Roman