Next step nearing paint??

[vettnut]

OK, I have applied a 2K urethane primer over my guidecoated, blocked down corvette with long boards on the old polyester primer. Should I start out guidecoating the new urethane with longboards, 320-400 grit? Or, would you start to wetsand down working down to 400-600 grit wet with hand held sanding pads?
Thanks

[Len]

OK, I have applied a 2K urethane primer over my guidecoated, blocked down corvette with long boards on the old polyester primer. Should I start out guidecoating the new urethane with longboards, 320-400 grit? Or, would you start to wetsand down working down to 400-600 grit wet with hand held sanding pads?
Thanks

If you think that this is your last coat of primer then block it with 400-600 but if it's going to need another application of primer to get it right then you can use 320.

[vettnut]

Thanks Len
Is 320 the correct grit under 2K urethane? In case I need to recoat this 2K Urethane with more 2K urethane primer?
I plan on mixing smaller quanities of this Urethane since it is setting up on me early. I may keep the temp in my shop a littler cooler say 60-65 degrees. I will have to clean out my gun every time I empty it to be sure.
Is there something else I should do to keep this 2K from setting up on me early?
DG

[Len]

Thanks Len
Is 320 the correct grit under 2K urethane? In case I need to recoat this 2K Urethane with more 2K urethane primer?
I plan on mixing smaller quanities of this Urethane since it is setting up on me early. I may keep the temp in my shop a littler cooler say 60-65 degrees. I will have to clean out my gun every time I empty it to be sure.
Is there something else I should do to keep this 2K from setting up on me early?
DG

You can use 320 under the filler primer just remember to apply your first coat of primer wet and allow it to flash before applying your second coat. This is usually the case for any paint product you're spraying just be careful not to shoot it so wet that it runs.

The 2K shouldn't be setting up that quick but if it is then you can refrigerate the primer and the hardener before it's mixed so that the hardening process slows down a little.

[vettnut]

I went to the local paint store and bought a gallon of 2K Nason urethane primer. Anybody else use Nason Urethane 2K primer?
I used up the remaining Evercoat Uro Fill. It was a struggle to get it sprayed out before it would begin to give me problems. Much of it went to waste. It would start to accumulate around the air horn's outside 2 holes. When this would happen the primer would begin leaving a rough textured surface, I believe it was interferring with the atomization.
I am using a Devillbis HVLP primer gun with a 2.0 tip. I later started mixing up smaller quanities, 20 oz. This is a 2K product 4:1. Example: 16 oz of primer to 4 oz of activator. This Devillbis is the same gun I sprayed numerous cans of polyester primer through without a problem.
Even with the smaller quanity, it started out great, flowing nicely, then minutes into it, began to collect around the airhorn's outer holes, causing the material to leave a textured surface. My paint salesman who used to be a bodyman could not explain this.
Am I doing something wrong? What's with this airhorn buildup?

I was wondering if I should have tried thinning it down, maybe with acetone for a better flow?
Thanks

[Len]

I went to the local paint store and bought a gallon of 2K Nason urethane primer. Anybody else use Nason Urethane 2K primer?
I used up the remaining Evercoat Uro Fill. It was a struggle to get it sprayed out before it would begin to give me problems. Much of it went to waste. It would start to accumulate around the air horn's outside 2 holes. When this would happen the primer would begin leaving a rough textured surface, I believe it was interferring with the atomization.
I am using a Devillbis HVLP primer gun with a 2.0 tip. I later started mixing up smaller quanities, 20 oz. This is a 2K product 4:1. Example: 16 oz of primer to 4 oz of activator. This Devillbis is the same gun I sprayed numerous cans of polyester primer through without a problem.
Even with the smaller quanity, it started out great, flowing nicely, then minutes into it, began to collect around the airhorn's outer holes, causing the material to leave a textured surface. My paint salesman who used to be a bodyman could not explain this.
Am I doing something wrong? What's with this airhorn buildup?

I was wondering if I should have tried thinning it down, maybe with acetone for a better flow?
Thanks

You could thin it a little to see what happens or you may be using a fluid tip that is too small for the viscosity of the primer.

[All Dry]

I usually block my surfacer with 180 until the final coat, when the final coat is on I switch to 400-600. Hope I havent been doing things wrong. Mike

[vettnut]

Len
The Evercoat instructions spec for a 1.6 - 2.0 tip for the Urofill. My Devilbiss primer gun comes with 2 tips. A 1.8 and 2.0. I used the 2.0 tip.
Thinner.
I purchased a gallon of Nason 2K urethane primer yesterday. It is a lower cost Dupont product.
Have you ever used it?
I have all but given up on the Evercoat Urofill. Sands beautiful but this airhorn issue has cured me of the product. I may email Evercoat but its probably a waste of time.
Is acetone the thinner of choice?
Thanks
DG

[Len]

Len
The Evercoat instructions spec for a 1.6 - 2.0 tip for the Urofill. My Devilbiss primer gun comes with 2 tips. A 1.8 and 2.0. I used the 2.0 tip.
Thinner.
I purchased a gallon of Nason 2K urethane primer yesterday. It is a lower cost Dupont product.
Have you ever used it?
I have all but given up on the Evercoat Urofill. Sands beautiful but this airhorn issue has cured me of the product. I may email Evercoat but its probably a waste of time.
Is acetone the thinner of choice?
Thanks
DG

I've used lacquer thinner with Slick Sand and it worked fine. I've never used Urofill but I would imagine it could be thinned the same as the Slick Sand. I've never used any Nason products.

[Bob K]

My Devilbiss primer gun comes with 2 tips.
DG

Is that gun a Finishline 3? Is so be sure that you have 23 PSI with the trigger pulled and check the vent holes in both the paint cup cover and the small black vent cap. One of them may be partially blocked. If not a Finishline 3 then you may need more air pressure.

Bob K

[junk]

I had similar problems when spraying 2K urethane earlier. I had about 3 things going wrong for me. 1.4 tip. My gun used 60 PSI and less air seemed to work better. Also it was a hot day and I was using fast catalyst.

I personally would play with air pressure. The 2.0 tip seems reasonable. I would also look at reducing it down if the tech sheet allows that.