Thread: Finish sanding

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800 to600 or 400 has alot to do if your sealing up the prime or painting on the primer with no sealer some of the sanding paper seams that it is abit coarser .on every day work at the shop i was at was 320 d.a then using the 3m gray back wet dry paper 400to600 the jobs that i wanted dead flat base i tinted the last coat of primer and sanded it out to 600 and shot base right on the primer

I've seen folks use 320/400 for final sanding, but I use 600 then do a final with 800-1000. I stopped using 3m paper for exactly the same reason Pat stated and went to either Norton or Mirka($$). For whatever reason, 3m has changed their manufacturing processes and it doesn't hold up.

A trick or two, tear the paper rather then cut it (fold towards the grit first then tear), another, soak the paper for about 30 minutes in a half bucket of water with a little squirt of Dawn dish detergent, then use a spray bottle with some of that kind of mixture to keep the surface wet while you sand. To me, it works slick!!!

I have sanded BC but you do chance making thin spots that show through, especially grays and silver (of course there can also be tiger stripes in those colors as well)

Do you guys over there not tint your primers body colour ???

Originally Posted by pat mccarthy

800 to600 or 400 has alot to do if your sealing up the prime or painting on the primer with no sealer some of the sanding paper seams that it is abit coarser .on every day work at the shop i was at was 320 d.a then using the 3m gray back wet dry paper 400to600 the jobs that i wanted dead flat base i tinted the last coat of primer and sanded it out to 600 and shot base right on the primer

Originally Posted by roadster32

Do you guys over there not tint your primers body colour ???

Speaking only for myself, light, medium or dark depending on the BC or SS

My personal preference is to first use 2 pack Epoxy primer and overcoat wet on wet with 2 pack hi build tinted to the colour of the car, that way any stonechips don't show so bad.

Originally Posted by IC2

Speaking only for myself, light, medium or dark depending on the BC or SS

Originally Posted by roadster32

My personal preference is to first use 2 pack Epoxy primer and overcoat wet on wet with 2 pack hi build tinted to the colour of the car, that way any stonechips don't show so bad.

This is what I used on my current build:
1- Nason and SPI epoxy primers (in this amount: 1qt Nason(Wescott front fenders, er wings only),5qts SPI, the rest of the steel Brookville body - Nason can't be sanded, SPI can)
2- SPI 2K primer - 1 gallon
3- Polyester high build primer - 1 gallon (sorry, I don't recall the brand, but it was recommended by a pro on another site)
4- Rage Gold filler - 1 gallon (half plus left)
5- DuPont ChromaBase 7 quarts
6- SPI Universal Clear 7 quarts
7- Presta 1500 to cut
8- Presta Swirl remover to buff
9- Rolls of 3M tape - guesstimate 4-5
10- Wet and Dry Sandpaper in grits - 80(a lot - I had to go to bare metal). 3-4 packages each of 220, 400, 600, 800, 1000, 1500, 2000. All was either 3M or Norton and a bit of Mirka (my favorite and a bit less then 3M)

And yep, tinting is the best way - I just don't do it. As you probably have found out - we don't have rough highways nor any chance of stone chips as the paving is smooth as silk, always maintained on our side of the Atlantic (now if you believe that, I have some very nice land in Florida..........)

The last 2 cars i've painted i've put 2 coats of epoxy over the hi build bfore top coat and they seem to be a lot more resilient to stone chips, Not sure why but they definitly are, both have been on the road now for 2 years without any chips.

Originally Posted by IC2

This is what I used on my current build:
1- Nason and SPI epoxy primers (in this amount: 1qt Nason(Wescott front fenders, er wings only),5qts SPI, the rest of the steel Brookville body - Nason can't be sanded, SPI can)
2- SPI 2K primer - 1 gallon
3- Polyester high build primer - 1 gallon (sorry, I don't recall the brand, but it was recommended by a pro on another site),
4- Rage Gold filler - 1 gallon (half plus left)
5- DuPont ChromaBase 7 quarts
6- SPI Universal Clear 7 quarts
7- Presta 1500 to cut
8- Presta Swirl remover to buff
9- Rolls of 3M tape - guesstimate 4-5
10- Wet and Dry Sandpaper in grits - 80(a lot - I had to go to bare metal). 3-4 packages each of 220, 400, 600, 800, 1000, 1500, 2000. All was either 3M or Norton and a bit of Mirka (my favorite and a bit less then 3M)

And yep, tinting is the best way - I just don't do it. As you probably have found out - we don't have rough highways nor any chance of stone chips as the paving is smooth as silk, always maintained on our side of the Atlantic (now if you believe that, I have some very nice land in Florida..........)

It probably provides a bit of cushioning effect with the added build. Some folks here just use multiple coats of epoxy with no poly/2K high build. The best that I've found here is the Southern Polyurethanes (SPI) which can be easily sanded for several days before it gets really tough then it takes some effort. It's like the high build polyester but a heluva lot stronger after final cure. When putting mine together, I nicked a couple of spots of the BC/CC but never even made a mark in the epoxy.

Originally Posted by roadster32

Do you guys over there not tint your primers body colour ???

yep i said i tinted the last to coats of primer .i did this some times used the ppg k36 i would use it as a sanding tint sealer but alot of times i just did not tint the primer if a good cover color .in the shop i work at i was painting evey day so you knew real fast what paint would not cover and there s a deal with the more solvent you hit the car body or that your painting with the move solvents are going to dive in and move stuff this is were getting all the body work done before you prime . with out all that poly putty sitting on the primer then moving around when your solvents dive in
if i walk round the car more then 4 times with a soild paint or clear then i would cut it flat and put more color on or clear this help s to so your not piling all the thinners on at the same time and when you cut the paint that helps let them get out as well but this was some time ago i know with the V.O.C theres less thinners .but you still have to watch them. that is were how fine you sand up to comes in to play as well. hirer the paint is cut with thinner or slower it drys . the finer you would go up with the paper