Getting ready to prep (stprolla and others come on in)

[Therian]

Ok guys, looking for some opinions from anyone that has done this before (or has researched it enough to be informed). Plan of action is as follows

sand car with 320 grit dry using D/A air powered sander
sand dings with 80 grit, fill, sand up progressively (80,180,320)
wet sand with 600
wet sand with 1200
wet sand with 2000

as you can tell, I want the prep to be immaculate, time is not a problem, I'll be off work for the next week and will be dedicating most of my time to this.

Questions:

1. is it necessary to wetsand from 600 to 2000? could I just wet sand on the highest grit? Or is it safer to wet sand from 600 on up.

2. Sanding bumpers...anything special here? no filling work is necessary

3. Anything to watch out for when buying D/A sanders? I'm looking at a campbell hausfeld model atm (around $85 CAD)

Any other tips, comments or advise will be greatly appreciated (though I don't want to hear anyone telling me to leave this to the pros...I'm confident that I can do this myself)

 

[bigcat]

most paint systems say you need about a 600 grit scratch for best mechanical adhesion. i would not use much higher than 600, but it does depend on the color. (mostly for mettalics, might use a little 800 or 1000 for better metallic orientation.) repairing the dings depends on the size of the ding.

nothing special to sanding the bumpers, just be sure to get into the creases and crevices.

get the best DA you can afford, and hold it flat to prevent cutting grooves into the paint. a HUTCHINS DA would be about the best, but they are over $200 easily.

 

[mo_dingo]

80 is way too coarse. Start with 400 dry and see what happens. You can always go lower grit if necessary.
Scott

 

[Therian]

80 is way too coarse. Start with 400 dry and see what happens. You can always go lower grit if necessary.
Scott

With regard to dings? 400 seems a bit high? I was under the impression you wanted to go a bit deeper before applying bondo

 

[bigcat]

if you have a ding, you are going to need at leaset 80 grit. again, depends on the size of the ding. see sig, i am ase certified bodyman.

 

[Therian]

I'm planning on painting it black again...so it would be safest to stop at 600 grit to promote proper adhesion then? Seems easier than continuing to sand before priming.

Do you suggest wet sanding with the 600 and then degreasing the car as the last steps before priming?

 

[bigcat]

wash the entire car with DAWN first. then wipe it down with another wax and grease remover. then start your prep work.

for primer, i would stop at 180 for the body work, but use 320 around that spot. just be sure that thre are NO shiny spot before priming (or paint). block the primer with 320 (assuming you dod your job with the filler, and are not trying to use the primer to do your body work).

after you spray your primer on the car, you can take some old pray paint an mist it on the primer, then block. that will show you the highs and lows. the highs will sand the guide coat (spray paint) first, if one area shows through before all the rest, thats high. if the guide coat stays on the spot while coming off the rest, then thats a low spot.

assuming that you did not go through the primer, and have enough on there to continue prepping for pain, start wet sanding the primer with 400, and then 600. if you have spots showing through the primer, i would reprime before doing this. if you prime and block the whole car, when you think it is ready for paint, you can run the water hose over the panel, and look in the reflection.

if it is smooth as glass, its ready for paint. if the reflections are distorted, its not ready for paint. spend more time blocking and priming as necessary. you dont want to rush this part, as if you paint it, and the body work shows, you will never be happy. if it takes a day or weekend longer to get it just right, thats time well. spent.

 

[Blackened302]

i agree w/ mo-dingo: 80 is too course. i'd start w/ 180 or 200. a little more work, but a lot smoother.

 

[bigcat]

you can t flatten a road with a rake, you need a bull dozer. you work your way up to finer grits. but again, it does depend on the ding. pics would end this debate.

 

[Blackened302]

also, i highly recommend a product called "autobody icing" that you can get at napa. it's expensive ($17 a tube) but it's a LOT easier to work with than bondo is.

check to see if the putty shrinks--if so, you'll have to do 2 coats

 

[95BLKGT5.0]

Listen to bigcat he knows what he is talking about
There is a web site that deals with body work and painting. It also has supplies,fourms,videos and expert advise.
http://www.autobodystore.com

Now if it was my black car (by the way I have been painting cars and boats for over 20 years)
1 wash with Dawn and then a good wax degreaser.
2 machine sand entire car with 120 grit
3 Epoxy prime all parts
4 Fill all dings and sand with 80 grit
5 Prime with a high build primer
6 block sand up to 600 grit (use the spran can guild coat to see highs and lows).
7 Spray with base coat then clear coat.
8 Block sand up to 2000 grit and buff.

 

[stprorolla49]

i think these guys have got it

 

[timeless2]

Listen to bigcat he knows what he is talking about

Don't encourage him--his head is about to explode.

 

[bigcat]