hey guys When I am doing bodywork what are some good ways to check to make sure everythign is strait? I put patchpanels in my bed of my 95 ford truck and i used the big ones they cover the entire side up to the trim line and only leave about a foot at the back of the bed orignal and the frotn about 16inches. the rest was cut out and the patchpanel was put in and welded into place. Now my question is how can i make sure that the bodywork I am doing is all strait? How can i check to find out if it will all blend in and look strait and not liek a ocean once i put paint on it? a the trim lin e i used a long streight edge. but below the trim line i can use the strait edge in some spots but some of it is going to need to have some of a curve to it also. So How can i figure out if it will look strait or not when i put paint on it? Please let me know.
thanks,
jimmy
PS I am using a boardsander to do most of my sanding i do have a block sander tho and also a DA sander.
thanks again!

 

one trick...use different shades or colors of primer then board sanding will show you high and low spots as you work through the layers. Use good light from the side and take care to spend time looking how it reflects light....especially with fresh paint... reflected light doesn't lie. Use a 24" or longer semi flex board on the big panels and attack it from a bit of an angle. Take your time...and don't over do it...i really screwed a job up recently by the last second choice to take more off...

 

Also remember to use your sander in a criss-cross patern over curved areas as opposed to sanding all in one direction. This will help follow the contour of the panel.

 

block your primer with as long of a board/block as you can comfortably work with in the area you are doing, within reason. If you only have a few inch square area, you don't really need to pull out the really long board. Watch you guide coat being removed, when all guide coat is blocks off and high spots cut down. After a round or two of primer / blocksanding with 180ish with a long board, if you did a good job with your body filler work, it should be getting pretty straight. You can kind get an idea how it may look if after sanding your 2k filler primer, you wipe the panel with some wax and grease remover and look down the panel from the side while its still a little wet. Not perfect but will give you somewhat of an idea. Most of its experience of feeling when things are straight, rounds of blocking and priming and hopeing you got it wave free when you start shooting your paint. Those waves and dents like to hide on you sometimes, and can show once in a while even though your hand tells you its straight.

 

ok after i got the panel sanded down to where i can feel very littlehighs and lows but cant really pin point them out what should i do? also how do i attack these parts? I dotn want to mess up what i have already cause its pretty smoothe now jsut need to improve on it and not mess it up worse.
thanks,
jimmy
ps please let me know!

 

If they are minor highs and lows, some more priming with a high build filler primer and block sanding should straighten things out. The more rounds of primer and blocksanding, theroeticly the straighter/wave free it should get as long as the filler/straightening work was done well and you are sanding with a long enough block. I like to use 120-180 for all my blocksanding and sand in a cross x pattern, except for if straightening a body line. Once everything has been worked and primed (however many times) then prime a final time and final sand with finer grit. If you use a long block you should be able to work down the highs and primer and guide coat will stay in your low areas. When you have it straight, all the guide coat should block off and you won't be sanding through to filler or metal in a bunch of areas. Just be carefull when you get to final sanding. You should use a backer pad or block also. If you start taking shortcuts and machine sand or sanding with you finger tips, you can put in waves you worked so hard to get rid of.

 

ok thank you very much next thing i gues i need is some highbuild primer. I know I do not wanna use spray paint primer (even tho it is sandable). I have been told not to use that. So i gues i need to get soem highbuild primer.
thanks
jimmy

 

Yeah, you really don't want to use lacquer primer. Some high build urethane 2k primer or polyester primer is you best bet for blocking-fill. I don't have much experience with the polyester primers, but they have the most fill, basically the same stuff bodyfiller is made out of in sprayable form. You will need a gun with a tip that can handle the primer you are spraying, or have to reduce it some to get it to spray properly, apply more coats. I put epoxy primer down on bare metal spots first and also over my bodywork shot prior to coats fill primer. The epoxy is non porous unlike other primers and will seal the surface and has great adhesion (like a glue)- to sanded or blasted bare metal too. It may be a little extra expense, but is worth the money spent. Typical epoxy primers don't sand real well or have a real lot of fill though. If you spray the urethane over the epoxy primer while its still in its time window (typically a few days at least, check the product sheets) you will not have to sand before applying the urethane 2k. You can just spray the high build without using epoxy primer, but for the best adhesion and corrosion protection, ect, I think epoxy is the way to go. Another thing to consider is the color of the primer, either try to pick one that will be the easiest to cover with your color paint, or spray a sealer to help coverage prior to painting. Most epoxy's and urethane primers can be reduced and used as a sealer. Have a paint supplier look up your paint code, and they should be able to tell you what shade primer to use for coverage. Dupont has the value shade system, and others have similar. Good luck.