I wonder if I could use the 3M dry powder guide coat that I have to help view the scratches in the door and carefully dry sand them out being that I cant see the scratches too well, but then dry sanding could open another can of worm potentially. Just a thought

Well spent 4.5 hours on the door after a hard day at work only to end up with more scratches in the end result again om the door lol.

Today I used 3m powder guide coat on the door and then tried to wipe it off to expose the scratches, it did not wipe off, then used the hose to wash it off, it did not wash off haha. So I took it off with 2000 grit by wet sanding. I had the hose constantly spraying water over where I was working . I used a flat 5" hard block.

Once I sanded all the guide coat off I dried it and hit it with the wool pad and M100 three quarters of the door actually came out pretty **** nice with no scratches but there were a few swirl Mark's from the wool pad which I guess is ok before polishing but the bad part was that other 1/4 of the door had scratches, so I reapplied the guide coat and sanded out the scratches with 2000 and just for the heck of it I hit it with 3000 grit on the whole door with a hard block, this time after the wool pad and M100 I had scratches all over the place again. I even have a 12" scratch now that is in a perfect straight line.

One thing is for sure, I'm definitely causing these new scratches each time. I just don't get it, I'm being careful to keep everything clean and keep the water on. Maybe I need to start with the basics, like the proper way to wrap sandpaper around your block when doing finishing work.

The guide coat is not supposed to wash off. It disappears when the surface is sanded flat.

I would check your equipment. Did you buy a quality wool pad? What kind of flex pad do you have on the buffer?

It doesn't make sense that half of the door would come out great and the other half has scratches after buffing.

Another thought, are you sure you washed all of the Heavy Compound used earlier out of the wool pad?

Robo999 wrote:I wonder if I could use the 3M dry powder guide coat that I have to help view the scratches in the door and carefully dry sand them out being that I cant see the scratches too well, but then dry sanding could open another can of worm potentially. Just a thought

I use this method as well when looking for perfection.

I have a 7" twisted wool pad made by Dewalt seems pretty good quality. I feel like when I'm sading blind with 3000 grit I'm cutting in new scratches somehow. The clear is kind of soft.

If you are working a 12"x12" section at a time, you should know immediately whether there are scratches or not. Keeping the sandpaper clean is critical and checking your work often necessary.

I don't even own 3000 grit paper as the buffer easily handles 2000.

The sanding is the critical part. If you are not getting the heavier scratches out you will be continually frustrated.

These parts are sanded with 1000, 1500 and 2000 and then buffed:

Wow those panels look amazing! Great job.. That's what I'm shooting for as I want to take this car to car shows this summer and want to have minimal imperfections also the reason I have been working on it for 5 years (not the paint part) but started sanding my first panel 2.5 years ago off and on.

When the guy at the body shop quoted me $15k to paint this little Datsun I almost went for it being that this will be a show car, but I thought now is the time to do this myself and learn as much as I can and oh has it been a son of a **** but I'm learning alot and hope to paint my 71 Chevelle that I have had for 25 years once I learn all the ins and out on this 240Z.

Tonight I went at the door again and sanded with 2000, it got late and really cold so I didnt have time to cut it but I think I see a few scratches in the hazy door I will have to go over it again this week before I cut it. I didnt realize how intricate this part is, I want to sand it like im sanding high build but you can't.

I got the door looking the best it has yet, if you stare at it long enough with the light hitting it just right you can see some imperfections, but all in all you cant tell there is scratches. It's not perfect but I think it's still show car grade. I ended up soaking my paper longer this time instead of 1 minute and I only did a 12"x12" section at a time, constantly using the squeegee and rag, having to look sideways so the light hits the panel just right to see if I still had a scratch that I CAUSED 5 seconds before, kind of like a dog chasing his tail but after hours more on this door it is finally done.

I can't believe how long it takes to do this right, or should say takes ME. But I guess for my first time painting my own car and doing my first cut and buff it is worth the experience. Now it's time to move onto another panel on the car. Have to fix about 30 runs in the clear all over the car and plan in using the glazing putty trick. The runs happened on my 3rd coat of clear when all the sudden my filter right below my gun clogged and dropped my pressure to 10psi causing the clear to fall out instead of it being atomized. Just my luck that happened, the 1st and 2nd coat were flawless oh well.

Thanks for the help.

You're welcome.

And welcome too, to the reality of high quality painting where the work before and the work after far surpasses the relatively small time behind the gun. If only more people understood this and that this is the reason why a good paint job does not come cheap.

Anyway, it's been interesting following this thread and your experiences.