Body Panel Fitting

[rockdogz]

Ok, I'm new at this part of the game and would appreciate any tips. I have new (repro) front fenders that I'm fitting on the body along with the old nose pieces (which look to be repros too, may need to replace), new hood, etc. Naturally, they're not lining up well on initial assembly. I want to try to fit them on before I do any finishing of the panels. I'm basically talking about the front end (fenders, inner fenders, upper and lower nose pieces, hood), doors, trunk lid. Here is my thinking as to the order of tasks - please let me know your recommendations from your experience...



1. initial fitting of panels, modify as necessary for best fit
2. remove panels
3. perform body work - straighten, prime, paint back side with zero-rust or regular paint? recommend spraying edges of panels with base for cut-in?
4. re-assemble panels, block sand, prime, repeat
5. ready for color

[68protouring454]

depending on color, i would panel paint the vehicle, but let us know color then we can go from there, even if its a mettalic the new paints are so far ahead of yesterdays paint that there is little trouble with panel painting a car, however i do like to paint everything at same time.
now yes pre-fit panels, hoeing out holes where needed, and getting everything aligned, take note to where and how many shims are needed, as this is key into getting it back together.
next do all body work inside and out, and prime and block sand, then prime and block sand some more, i would then paint back of panels, with your choice, something semi gloss to not draw attention to itself, i like evercoats paintable undercoating, it dries in 30 mins and leaves a bit of a textured finish, its cheap too, 6 bucks a can, best stuff out there, then tape off inside of panels and prep and clean for paint, if you do not mind overspray on inside of panels i would not tape them, there are only a few spots you will ever see once done, goodluck
let us know
if you do paint with fenders on just tape off engine bay, etc and do all basecoat at same time, have doors off and tape interior off and do jambs all at once, much cleaner for someone who does not do alot of paint work, as you can get some bad tape lines,, goodluck
jake

[Happyfunballs]

If you're looking for a dead-nuts straight car, you better block with all the panels installed and shimmed. Same process, just imagine the seams don't exist. You block from one panel to the next without segregating the panels. What you might find is that a little hammer and dolly work is necessary on the back of the fenders and front of the doors....the stamping process causes them to bow on the edges.

[rockdogz]

Color will be black, like my avatar pic. I was going to panel paint but I'm really nervous about scratching everything to hell when I try to re-assemble. That's why I want to try putting everything off and on a few times to see how it goes. Plus if I paint myself, my compressor isn't going to be large enough to paint the whole car assembled.

[68protouring454]

like happy says that is the best way to do it, but a straight panel is a straight panel, you just have to know how to feel the panel, and watch the material when sanding, however i would assemble car and just paint with doors off, that way fender jamb and door jamb will have no taping, then 4-5 days later tape edges of jamb up with 2-3 layers of tape and install dorrs with a trusted friend, if you do not do body work for a living i would not worry about block sanding the car with all panels on,. however having as much on the car as possible will eliminate chips and scratches, a few layers of masking tape will save you, goodluck
jake

[68fusion]

Lord dont do bodywork on those repo's off the car ...they will not fit after that...I did a 69 with "repo" fenders and bridged and made gaps had everything perfect as one could get with the POS ...took them off, primed them and blocked them on a stand and just blocking them warped the bow contour on the side, the one that is adjacent to door...had a hellva time getting the panels to line back up again. Just my opinion, I would far rather have patches welded in GM stuff than those fenders, doors or trunks. The quarters are sorry too but atleast your cuting and fitting them anyway so you can doctor them to fit.
GOOD LUCK...

[Buford's Customs]

An easy way to see what your painted panels will look like ahead of time is to use a wax and grease remover. Wipe it on the panels and it will wet them and give a great shine, this is what your panels will look like after paint. Paint gives gloss but will not hide anything. this trick will work after primer is dry and you start blocking. As far as painting apart if I was going to paint a car black I would try to do it in pieces but spray everything inthe same session. Just my two cents, and they are worth just what you paid for them!

[68protouring454]

sounds like your a little heavy on the block sanding, man take it easy, or support the part being blocked properly so it is not bowing when blocking it out, the urethane primer and polyester i use sand very easily
oh yeah, i would highly reccomend polyester primer for your car, it will straighten hail damage to an extent, the good stuff builds 40-50 mils in 5 coats, block with 180-220, then urethane prime and block with 400-500, now your ready for paint
jake

[Happyfunballs]

If your car is going black, you better make friend with your sanding block, cause you two will be spending alot of time together. Also, panel painting a black car is acceptable. Fenders on, doors off is an excellent idea. There are many different ways to get you the result that you are looking for. You will need to be extra carefull with the bodywork to make sure that everything is straight. Black is not very forgiving....it's shows everything. Block sand until your fingers bleed....once you've reached that point....block it again. Remember, it's supposed to be fun.

[63SW]

Just reading the posts i was wondering , since it wasnt mentioned and he say's he's new at this part .
Does any one else use a GUIDE COAT and and do a final blocking with wetsanding ?

Im definately no professional but i agree that having the panels fitted and blocking them on the car while assembled is the way to go for a straighter finish.
Once your satisfied , remove and paint .
Another thing is ( if you dont have a decnt booth or are doing it at home ) you will get less dust panel painting , especially if you hang panels at a angle where the dust cant fall on it ... Like hanging a hood rather than laying it flat.

Like Buford's custom said " Just my two cents, and they are worth just what you paid for them! "

[Happyfunballs]

I would assume that guidecoat is a given. I'm sure we all use different methods. 3M makes a really good fine guide coat, but that cost some money(don't use it). I preffer the $.99 flat black spray bomb guide coat. The cheaper the better. Using a guide coat is the best way to find high and low spots. I final block with wet most of the time....it depends on the job and my tolerance for cleaning up a mess.

[68protouring454]

yes i always use guide coat when blocking, and i have recently started wet blocking the final coat of urethane primer, you can go either way dry or wet on the final sand, and i yet to like either way better, however uide coat is critical as well as your feel, watch the guide coat carefully to see where and where its not coming off, once urethane primed you need to use a polyester putty not bondo, these sand alot easier and the bodywork should be close before primeing so you will only have a few spots needing more attention after primer, goodluck
jake

[rockdogz]

Thanks - I appreciate the help.

Couple other questions - I have polyester primer, but what about the urethane - is it the same as epoxy primer or different? It's not etch primer, right?

Also, do you recommend leaving the front and back glass off to paint, or is it just as easy to mask the glass as it is to mask off the open space?

Thanks,

[Happyfunballs]

Found this as a good way of explaining the difference, although this doesn't need to be taken so literally:

Each has it's own unique characteristics and purpose. Epoxy is used for strictly adhesion properties before final painting. Epoxy is sprayed on and the paint is applied before drying and without sanding. Urethane is used as a primer or surfacer for working the metal into shape. It too can be painted over just prior to it's drying or can be allowed to dry completely and then sanded and painted.

Etch prime is strictly used for the priming of bare metal. As for the glass, if you can paint it with it out, I'd do that. Inevitably, overspray always finds it's way to the glass. Otherwise, taping it off, while in or out, is basically the same.

[Buford's Customs]

I have more to input the epoxy is a water proof barrier so it will work to protect metal, you can put the epoxy down allow it to dry then do your body work on top of it (body filler work). You must sand it slightly before putting bondy filler on top, many OEMs require this for your work to meet their warranty. after you are happy with your body work you proceed to building prime (urethane) Guide coat this after it dries or else the guide coat will penetrate the wet primer, then I like to dry block with 180 grit on a long (16'') block. I usually reprime reguide coat then wet sand with 320/400 after this you can use the epoxy for a sealer to help fill minor sandscratches and help with adhesion. Try to select products that are high in soilds the solids in paint products do the work solvents justs evaporate from the film and give you shrinkage. I try to end up with under 9 mils of primer and 5 mils in the topcoat paint or clear. this will help the paint job last longer. If you get much thicker than this you could end up with a dried up lake look after a couple of years.

[68protouring454]

i am with buford
etch primer is for bare metal, after bodywork is done, should not be applied under bondo,this etches metal for adhesion and adds corrosion protection.
epoxy primer, has etching primer properties, but it also seals the body up if it will see any moisture, also you can use body filler on top of it, and it is good for long projects at home shops.
polyester primer is polyester and is super high build with very low shrinkage, block with 180-220, then urethane prime
urethane primer is a high build primer but you can paint over urethane just block with at least 500 grit before doing so.
sealer- is what you would use over a etch primed or epoxy primed panel that needs no body work, thus needs no primer.
lots of guys like sealer but there is no need for it on a complete urethane primed car, just make sure to hit burn thrus with more primer and sand those spots, that way you have uniform coverage.
thats why sealer is used, to make a nice uniform ground coat for the basecoat to go on.
sealer only adds a chance of more dust in the paint and to add to the orange peel, as it is a wet on wet application.
if i were you i would
sand car with 80 grit or so, do all body work etc, then hit bare metal with etch primer, then spray with 3-5 coats of polyester primer, guide coat, block sand using 180-20 paper, use as long of a board sander as possible on the panel, then once happy urethane prime and either dry or wet sand with 400-600, if any burn thrus happen, re-apply urethane primer to those spots and re-sand thos areas, once even, prep and paint, goodluck
jake

[68protouring454]

i am with buford
etch primer is for bare metal, after bodywork is done, should not be applied under bondo,this etches metal for adhesion and adds corrosion protection.
epoxy primer, has etching primer properties, but it also seals the body up if it will see any moisture, also you can use body filler on top of it, and it is good for long projects at home shops.
polyester primer is polyester and is super high build with very low shrinkage, block with 180-220, then urethane prime
urethane primer is a high build primer but you can paint over urethane just block with at least 500 grit before doing so.
sealer- is what you would use over a etch primed or epoxy primed panel that needs no body work, thus needs no primer.
lots of guys like sealer but there is no need for it on a complete urethane primed car, just make sure to hit burn thrus with more primer and sand those spots, that way you have uniform coverage.
thats why sealer is used, to make a nice uniform ground coat for the basecoat to go on.
sealer only adds a chance of more dust in the paint and to add to the orange peel, as it is a wet on wet application.
if i were you i would
sand car with 80 grit or so, do all body work etc, then hit bare metal with etch primer, then spray with 3-5 coats of polyester primer, guide coat, block sand using 180-20 paper, use as long of a board sander as possible on the panel, then once happy urethane prime and either dry or wet sand with 400-600, if any burn thrus happen, re-apply urethane primer to those spots and re-sand thos areas, once even, prep and paint, goodluck
oh ya alot of american paints use one primer as a high build and as a sealer you just mix it different, i do not like these products as its a kinda one size fits all, works but not the best, i like to use a etch primer, a polyester primer, a urethane primer, a dedicated sealer if i have to, and so on

jake