Block Sanding?

[SuperC10Tex]

Originally Posted by hugger6933

When you look at the pics and ask yourself self, is this smooth enough to paint? How do you answer yourself? You know me enough to know that the last thing I want to do is hurt anyones feelings and the second from the bottom on the list would be talk about their work because this stuff aint easy! Now my concerns are as follows, in the first pics I still see some sand scratches. I know this is gonna sting like a big red wasp, but I would if it were mine and I were faced with this panel, get out the da and some 220 grit and sand it over again the prime another coat of high build. Once it is flashed I would da dry sand 400 grit or 600 grit depending on the color choice. You have all the blocking out of the way, and if the pad is known to be flat your not gonna hurt any thing by sanding with the da as long as you don't tip the pad to "dig" the primer[ that is a big no no].
If you don't do this I'm afraid the small craters that we can see so clearly will be magnifyed once clear is put upon them. Nobody wants that. Good luck and no grumbling at me while sanding. [See I even customized my tag line for you] Jim

Thanks Jim! Two things before I break out the high build. These "craters & sand scratches" are not visible to the eye. The pics are magnified big time. Also, I am doing the top coat in SS black.....Change your opinion any?

[Stepside Jim]

Hi, I'm in agreement with hugger6933 on the texture needing to smooth the small pits showing it the pictures. The smallest pits do like to magnify themselves later in the paint and now is the time to remove as many possible eye sores that you may regret later.

One thing that may save time is.... How much of the high build primer is on the vehicle now?

What I'm saying is; with your final sanding in the pictures you may have enough material (primer) built up that you can go back to a 220 grit wet sand and remove the top rougher primer and sand til the primer is level and all pits are removed. Then go back to the 400 grit to remove the 220 sand marks.

Get Jim's approval first, but it may save you from having to spray again, this way you could use the material that is already on the vehicle.

[Cape Codder]

Spray a light guide coat on it and wet sand with the 400 and a block till the guide coat is gone from the texture. You may not need to reprime depending on how much primer is there. Paint hides nothing and doesn't really fill much.

[hugger6933]

How many re primes have you done? Were they 2 or 3 coats at a time during each re-prime? If you think you have plenty of primer build mil thickness go ahead and guide coat it and put a known FLAT 6 inch D.A. pad on your sander and with some 220 grit sand the panel over again. Now the reason I say use a known flat pad and keep the sander flat don't tip it or tilt it that will hurt what you have done by blocking. By in keeping it flat you shouldn't disturb any of the block work already done your just removing material and trying to get back to smooth areas again. Now you say this is magnifyed , how blown up is it? I would like to know so I can compare it to some different primed stuff at my shop just as a informal test. Jim

[Cape Codder]

I'm not sure an amatuer should be doing finish work with a DA. Just my two cents. He is trying to do the best he can and not charging anyone by the hr. I would stick with just wet sanding with 400 and a block. How long could it take? 30 to 40 minutes per panel.

[wilkin250r]

I'm not a painter my any means, but I'm a decent machinist, and it takes a LOT of practice to get good with hand-machining tools. I agree with Codder 100%, if you cannot describe yourself as an "expert" with the DA, then I would sand by hand.

[SuperC10Tex]

Originally Posted by hugger6933

Now you say this is magnifyed , how blown up is it? I would like to know so I can compare it to some different primed stuff at my shop just as a informal test. Jim

Jim, that is taking my IPhone and getting it as close up as possible with being in focus and a back light, then blowing that up before posting it. Please do take a close up of your finished primed work and post it....Please.

Originally Posted by Cape Codder

I'm not sure an amatuer should be doing finish work with a DA. Just my two cents. He is trying to do the best he can and not charging anyone by the hr. I would stick with just wet sanding with 400 and a block. How long could it take? 30 to 40 minutes per panel.

I am going back and hand sanding with 400 backed with a foam pad dry, me and the DA do not get along. I shot the Cowl yesterday, material was to thin....no Orange peel, but a couple of nasty runs!! Going to let it cure, then sand them out and shoot again.

[hugger6933]

[/QUOTE]can't please all

[hugger6933]

maybe I shoulnd't try as hard to help if I'm gonna get jumped

[Chrysis]

Jim, I think he was asking you to do the same so he could compare, not as " lets see if you are any better". At least, that's how I read it. Honestly, I'd like to see what a macro surface view of a professional block sand would look like as well. So I would know if I achieved it. It would help me know when I should stop and move to the next level.

Please don't stop giving advice Jim, your input is invaluable to this forum.

Chryss

[SuperC10Tex]

Originally Posted by hugger6933

maybe I shoulnd't try as hard to help if I'm gonna get jumped

Jim, hope you don't think I jumped you? I just wanted to see a close up of a professionals work so I can know what mine should look like. Always in enjoy your honest opinions!!!

Originally Posted by Chrysis

Jim, I think he was asking you to do the same so he could compare, not as " lets see if you are any better". At least, that's how I read it. Honestly, I'd like to see what a macro surface view of a professional block sand would look like as well. So I would know if I achieved it. It would help me know when I should stop and move to the next level.

Please don't stop giving advice Jim, your input is invaluable to this forum.

Chryss

Thanks for helping me out!!!

[hugger6933]

No Tex, I was not talking about you just the ones that thought I had given bad advice. I felt and still do that if you have come to this level where your this close your able to turn down the rpm on a D.A. sander enough with a pad that is flat[that you know is flat that is critical]you should be able to take of primer without removing filler or putty or anything that has so much fill properties that you are gonna create a "wavy" situation. O the very last job I had in the shop[The 03 Tahoe I'm driving today] It had a tree fall on it during a storm I bought it it had damage to the hood, the right door was toast and I replaced it from my stock and the roof had damage as well. The hood damage was a trench about a14 inches long right in front of the passenger s view from the seat middle of the hood about 3 inches wide at its widest and kinda deep. I was able to hammer and dolly a lot of it but what I couldn't I pulled with the dent puller and then filled. Any ways after blocking and the priming the whole I ended up going over the whole body spot areas with a da sander. I didn't paint the entire hood or truck just the areas with primer plus a little on each side and it blended the body spots well are gone like there supposed to be. I just think that the sander is not gonna hurt you here. I you have any doubts pull back out the practice panel I had start with. work on it first it should have primer on it. Or if your nervous about the amount of work put in and the thought of it maybe getting messed up, hand sand it. Now lets go back a few steps do you still have that practice panel we talked about? is it in high build primer yet? I would like to know if it has the same look to it as the panels that we are talking about here. How much air are you running at the gun? Does it seem like enough or does it seem to you like it needs a little more? Does the primer have a rough texture at all after it is sprayed onto the panel? Some of those pics look almost as if the primer went on too dry is the reason for all of these last questions.

[Cape Codder]

One of the things I was told when starting in this business was that everyone had a little different way to do things. If you pay attention and see what works best for you you can learn the best habits from each person you work with. The shop I started in was a GMC truck dealer but you started out sanding everything from pickups to big rigs. I wasn't allowed to use a DA till they felt I could sand correctly by hand. No finish work for over a year. If you are working on a flat panel or a convex curve a flat da will do fine if used correctly but on a concave area you can easily burn through the primer and be back to repriming again. After 40 years of doing this I only use a DA to rough out bondo work,feather edge repairs or strip panels. I enjoy hand sanding and find it quicker in the long run. This is what works for me I know many guys that do it differently with just as good a result. There are many ways to do something right but until you refine your skills a power tool can cause more work in my mind.

[Rocketman72]

Originally Posted by SuperC10Tex

Okay paint Gods, below are two close pics of my surfaces. Is this smooth enough to paint? Block sanded with 180, then went to 400 dry.....

NO! That surface should be as smooth as glass. No craters and no scratches deeper than 400grit sandpaper.

[Cape Codder]

I think the magnified close ups throw the perspective off. Guide coat sand till gone, done.

[LF_MN_71GMC]

Haha, I feel this pain (literally, my arms and hands hurt). There's been nights where I look at it, say out loud, oh screw this, I'm painting it in the morning. Get out there in the morning, look at it, and start sanding again. Haha

[Cape Codder]

I'v been sanding since July of 1974 and the only time I can remember my hands really hurting was last year when I stripped the paint from the grille of my truck. I wet sanded with 220 through 3 or 4 layers of paint till down to plastic, primed and resanded for paint. I sanded skin off that weekend.




I think it was worth the effort.

[SuperC10Tex]

Well, today was the day! Temp = 72, no wind, no humidity....time to lay down some paint! Started with the doors, first one was good until some fish eyes popped up, second door ran across some orange peel. Moved on to the fenders....went much better. Corrected the door, all is good. Couple of small runs, little trash, but all and all, it will work. Tomorrow, the hood!!! Lot more respect for you guys who do this for a living, for sure!!!Enjoy pics below.....

[Cape Codder]

Looking good, I wouldn't worry to much about orange peel, as long as you have plenty of paint you can cut and buff that. It is easier to cut orange peel than runs. For runs I would give it good drying time and lightly scrape them with a NEW razor blade held 90 degrees to the surface till almost flat. Then block with 600,1000,1500,2000, and buff. The will go away. By scraping them flat you have less chance to sand through the area surrounding the run. You might even think about creating a run on some scrap while painting the hood to practice on.

[hugger6933]

If you have many runs to deal with there is a tool [isn't there always a tool] that is called a run razor. it is a holder for a single edge razor blade and it has a set screw in the center so you can set the depth of it . You can slide the blade in the holder then tighten up the screw then slide the tool down the run and it peels off the run with the edge of the blade.
How many of you have read my post about the blending or the tips about the razor on the high build primer edges? Well in those post I typed about the edges of the primer and the tape lines sometimes being too close together and meeting and when untaped there is of course a buildup line. Before sanding one way to help make things go MUCH faster than just trying to sand that line flat is to take a single edge razor blade and hold it at about 45 degrees away from you and drag it towards you. With the right amount of pressure on it [the blade] the line will peel off and the big tape line will almost disappear. That same principal applies to a run with the exception of the angle of the blade, you may need the blade more at 45 degrees towards you instead of away from you. That will make a huge diff in the way it cuts so you may need to practice on your spray out panel. Good luck and happy sanding. No happy buffing. Jim

[Cape Codder]

Hugger,I never heard of cutting the tape edge with a blade but like the idea. I have always rolled the tape back to try to minimize the edge, but sometimes I still have that hard edge that takes some work to feather out. I find that this is an ever evolving,learning business. To cut runs I have found 90 degrees or a right angle dragged towards me works best and I like holding a blade in the hand as I can feel what it is doing better. Years ago I bought what is called a run file but never had much luck with it and it hasn't left the tool box in years.

[faribran]

I have read and learned lots of very good tips from HUGGER thru the past few months.
Thanks sir.

[SuperC10Tex]

Got the Hood all "Cut", doors and fenders soon to come, then time for "buffing". Jim/Hugger/Paint Master, how does it look so far?

[hugger6933]

Looks good Tex, I'm gonna give it 3 out of 10 NO, just yanking your chain it is very nice looking work there. You have something to be very proud of! Your hard work and efforts have paid off. Just look at those parts and stare for a moment and say I did that, and anyone around you that can hear that will be amazed too. It almost looks like licorice candy and you just want to bite it. It really feels good to get your hands and mind together to make something like that happen doesn't it? Jim

[SuperC10Tex]

Originally Posted by hugger6933

Looks good Tex, I'm gonna give it 3 out of 10 NO, just yanking your chain it is very nice looking work there. You have something to be very proud of! Your hard work and efforts have paid off. Just look at those parts and stare for a moment and say I did that, and anyone around you that can hear that will be amazed too. It almost looks like licorice candy and you just want to bite it. It really feels good to get your hands and mind together to make something like that happen doesn't it? Jim

Thanks Jim! I do take pride in what I have done with my own two hands, I give it a 6 out of 10. Few little things here and there that I would have done different given another chance. I have gained way more respect for you guys who do this for a living. All-in-all for my first paint job, not even close to show quality, but just fine for a weekend warrior....