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-   -   Scratches in the primer filler after blocking (http://www.hotrodders.com/forum/scratches-primer-filler-after-blocking-73510.html)

Scode68 11-05-2005 10:19 PM

Scratches in the primer filler after blocking
 
I need some suggestions!

I sprayed the roof of my Mustang with DuPonts URO 1107 Filler Primer. After blocking the roof with 400 for four hours all I was able to do is knock most of the texture off of it. I then switched down to 240 and back up to 320 to 400. I know have scratches from the 240. Other wise the surface is nice and smooth. Should I use a putty to get rid of the scratches, spray the URO as a sealer and re-hit it with 400 and higher or maybe something else? The URO can be used as a filler or a sealer I think if I shoot more filler on there that I will end up with the same thing again.

I used the 1104 in the past with a conventional gun, which is a medium gray and it sands fairly easily. Now I switched to the 1107, which is a dark gray, and I applied it with a HVLP gun. The darker stuff seems harder than the lighter colored stuff to sand. I switched to the darker color because I plan on using a dark base coat.

mrcleanr6 11-05-2005 10:25 PM

if you have it blocked and flat and there is still enough primer on it just take an orbital with a soft pad and 400 and go over it to take the scratches out. if you need to then spray another coat or two of the primer but reduce it 25%. let cure then sand it again. you dont need putty. the primer is enough to fill sanding scratches.

Scode68 11-05-2005 10:35 PM

As a filler I mix it at about 4:1:1 and as a sealer it is mixed at 3:1:2. Sealer has one less part or URO but one more part of reducer. Do you think the sealer will fill in the scratches? The base coat will be the Nason Ful-Thane and is mixed at 8:1:3 but then again Iíve seen some tech pages saying 8:1:2 so I guess I have to play with that also.

mrcleanr6 11-05-2005 10:44 PM

just mix it as a primer filler 4:1 but add an extra part reducer. 4:1:2. this will just let it lay down a little better. allow a little extra flash time between coats. 220 scratches aren't deep at all. one or two coats should be fine then sand with 400.

Bee4Me 11-05-2005 10:56 PM

What Jim said. :thumbup:
I'd do some test shots with the Ful-Thane. Depending on what color it is and adjust the ratio of reducer from that.I'm not talking a short 1'x1' panel,PAINT a piece about 2'x3' wide.
If it's a metallic or light color,I'd go with the heavier base ratio. Nason does not cover for crap so the more pigment you got,the better.

chadsbodyshop49119 11-05-2005 10:58 PM

can you just sand it more with 400 grit to get more scratches out.. if you just seal and paint it there's a possibility that the sealer will shrink into the scratches. so either sand it more, or put a few coats of primer down and then sand with 400

Scode68 11-06-2005 08:07 AM

I did wet sand it also later yesterday with 400 for 2-3 hours more and I still see the scratches. I havenít painted in a while and I'm use to the lacquer based fill and sand primers being so easy to sand. How much time would it take to block the average roof with one of these new primers? I donít want to DA it because Iím afraid of creating unevenness.

roger1 11-06-2005 09:42 AM

With the last primer I used which was Evercoat UroFill 2K filler primer, I would estimate that it would take me about 30 - 40 minutes to block that top out with 400 dry on a long board and another 20 - 30 minutes with 500 or 600 wet. Then it would be good to go for a topcoat. (Assuming the top was in good shape to start.)

If the top had some waves or dings, I would go start out blocking with 180 dry then put on a second coat and block with 400 dry and then wet with 500 or 600.

7 Hours up to this point? Something is way wrong.

adtkart 11-06-2005 09:54 AM

You said that you "wet sanded" with 400. That may be one of the reasons that it is taking so long. I would be dry sanding it with 400 on a block if it was me. If you want to "wet sand", it should be just prior to painting, just to remove to final extremely fine scratches, and with the finest paper that you plan to use. I usually use 600 or 800 for that step.

JMO

Aaron

chadsbodyshop49119 11-06-2005 10:36 AM

Quote:

Originally Posted by roger1
With the last primer I used which was Evercoat UroFill 2K filler primer, I would estimate that it would take me about 30 - 40 minutes to block that top out with 400 dry on a long board and another 20 - 30 minutes with 500 or 600 wet. Then it would be good to go for a topcoat. (Assuming the top was in good shape to start.)

If the top had some waves or dings, I would go start out blocking with 180 dry then put on a second coat and block with 400 dry and then wet with 500 or 600.

7 Hours up to this point? Something is way wrong.

I'm with this guy other than the fact that I do everything wet... It kinda sucks but it seems i get better results this way everytime.. so I stick with it.. but I wish you luck... and as far as sanding time goes it's about the same for me as roger, but a little long with the 400 cause of sanding wet. about a hr or so..

Scode68 11-06-2005 10:46 AM

Quote:

Originally Posted by roger1
With the last primer I used which was Evercoat UroFill 2K filler primer, I would estimate that it would take me about 30 - 40 minutes to block that top out with 400 dry on a long board and another 20 - 30 minutes with 500 or 600 wet. Then it would be good to go for a topcoat. (Assuming the top was in good shape to start.)

If the top had some waves or dings, I would go start out blocking with 180 dry then put on a second coat and block with 400 dry and then wet with 500 or 600.

7 Hours up to this point? Something is way wrong.

Maybe I have to cut down on the activator? I knew that it was taking too long! Iíve mixed everything like I did in the past other than using the darker shade and applying it with a HVLP gun.

roger1 11-06-2005 11:12 AM

I would mix it to exactly like the instructions state with the exception of adding 10-20% (of the final mix) reducer in order to get it to lay down smooth.

Scode68 11-06-2005 11:30 AM

why is it so hard?
 
Kind of sounds good but why is it so hard? Would a slower or faster reducer make it harder sanding?

roger1 11-06-2005 11:45 AM

Quote:

Originally Posted by Scode68
Kind of sounds good but why is it so hard? Would a slower or faster reducer make it harder sanding?

Not having used that particular primer, I can't answer that about hardness. However, I find it unlikely that it would really be much different from any other 2K filler-primer. Maybe someone else who has used this Dupont primer can chime in and confirm that.

No, type and amount of reducer won't affect the hardness of the primer once cured.

You do need to get the proper sandpaper and sanding board if you don't have that. Get a roll of 3M P400 "Stikit" paper. The board I use is a 3M "Stickit" part#05444. In fact, I have 2 of them. I also keep on hand rolls of P180, P320, and P400 for these boards. This paper is for dry sanding only. IMO, dry is the way to go on primer except for the very final pass.

chadsbodyshop49119 11-06-2005 12:31 PM

Yeah it's hard to say,, if your new to this you'd probably think all primers are hard, it's not a easy task to do this stuff as many people think.. when I first started doing body work it took me a while to get a panel done,, but after doing it you just learn things that seem to make it quicker... and for me these things are hard to explain, it just happens i guess with experience.. But keep going at it you will get it sooner or later... but on a side note are you sure that your not seeing 400 grit scratches... you can see them a little, maybe that's what your seeing... this is why I sand to a finer grit before sanding.. and also why many people will base a vehicle, let it sit all night and scuff it the next morning and then base and clear...


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