1500 grit OK for more clear????

T

Toeknee

3 coats of Universal clear was applied and wet sanded from 1200 to 1500 grit found some flaws in basecoat.I plan on re-spraying and blending base on rear quarter then shooting entire quarter with 3-4 more coats of Universal clear. Will the 1500 grit finish give enough "bite" for more clear to be applied over????????Paint is a solid white ford paint code Z2 if that matters.
 
yup have to agree with old soul. i have tried masking and spraying stripes and graphics on 1000g sanded clear and had slight adhesion problem. base will peel off it. 800 grit you wont see that happening. i always do my graphics and airbrush over 600 but never over 800. any finer and your lookin for trouble.
 
So should I scuff the panels with grey 3m Scotchbrite or wet sand with 800 grit ?????
 
Most body shops blend panels everyday that are no more than scuffed
with a gray Scotchbrite with scuffing paste, it's standard procedure.
That's all they do for new bumpers too.
The most important thing is making sure it's clean.
If it's really clean it's stick fine.
I prefer 600 only because it flattens it better for
a straighter final finish, but it's not because of adhesion.
 
Thanks for all your help. I figured the 1500 wouldn't have enough bite just wanted to double check
 
Barry tested this awhile back and I think the gravelometer showed decreased adhesion with grits finer than 1200, rub it down with a grey scotchbrite
 
Standox TDS says to use 800-1000 on repair, prep rest with 1200-1500 and finish with a gold pad with paste or a Trizac 1000.
 
It's not always practical to sand blend panels flat with 800, especially near areas where the application of color might be a problem, but since 3M rates their #7448 grey pads at about 800 grit, they are ideal for areas near the next adjacent panel where sandthroughs might be a problem., and also for abrading edges and tight contours where sandpaper is a pain to use well.
 
I didn't want to start a new thread for my smiler question. When you say sand with 800, is that wet or dry? I just cleared a few panels yesterday, but had some runs and I'm sure I sanded off more clear than I wanted to trying to remove them. I went over the panels with wet 800 grit and now I want to reclear with a few more coats. Is that wet 800 ok, or do I need to go over everything with grey scotchbrite? Also, is one day enough to wait to re-clear or do I need to wait even longer?

Bill
 
For re-clear, use 400-800 but tread lightly by edges, use grey scotch to degloss shiny spots around edges and corners.
 
Wet or dry should I believe leave the same sand scratches, I only wet sand to remove swarf and keep my paper running a bit longer.
 
Wet sanding makes no dust but runs in all the cracks and any residue should be carefully rinsed before it is allowed to dry. Dry sanding makes a lot of dust but is sometimes easier to clean up in a way. It's just personal preference. I've been doing more dry sanding because of the water running into all the cracks in the vehicle making a mess, plus with dry it is a little easier to gauge progress on surfaces that won't be guide coated. All that said, wet sanding does a great job, and if you hate dust it is the way to go.
 
I prefer wet sanding but rarely do it anymore.. It's messy and cold in the winter. My feet don't like being in water all day anymore..
 
For coarse sanding clear, dry works real good.
I wear a cotton glove on my left hand and sand with my right,
wiping as I go. Doing it that way really lets you see the
results as you go so you don't over sand any area and you
get it all real thorough.
 
hand sanding with 320 or 400 dry gets my vote for sanding for flow coats, easy to see what you're doing and saves time
 
I have never tried as course as that Bob I always go at 600-800, will give that a go next time.
 
Barry did a gloss test on flow coating once using 400, 600, 800, 1000, and 1200. The 400 won and he was using a gloss meter. I was skeptical of 400 at first always went to 600, but his universal covers like it was never a problem, besides the coarser the grit the sooner you get done. I know how much we all just love to sand !!!!
 
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