Paint prep'

[crankedup]

I've decided to prepare my old car for a fresh coat of paint, change of colour. Looking at buying an orbital sander to do the job of wet and dry prep' but I'm flumoxed by the discription of the sanding disc's that are used by the power sanders. Will I be OK to use an 'alluminium Oxide' grade 80 and grade 120 to sand with? Any help appreciated.

[Mr OCD]

The trick with sanding is to work removing scratches that have been caused by the paper used before it... P80 / P120 is VERY course paper... it will remove paint and leave heavy scratches...

IMAHO if you are wanting to prepare the car for a respray then start off with P400 and gradually work up to P1200 to finish...

Prime the car with a high build primer then level off with P1200 and P1500...

Hope that helps.

Scott

[crankedup]

Thanks Scott, I was hoping to 'take the gloss' off existing paint and then apply my undercoat to that, I'm coach painting it. I presume the 1200-1500 paper is available for these orbital sanding machines?

[52classic]

IMHO you shouldn't need any sort of mechanical sander to do the self prep for a respray. Except a small angle grinder to start off any repairs.

Working at home is different procedure to the proffessional bodyshop.

I'm no expert, but the procedure I use is to mark damage and imperfections with a felt pen. Grind those areas back to bare metal with 40 grit on the grinder.

Do your best with the panel beating and/or welding then fill with Polyester stopper filler. Shape that with 80 grit freecut paper on a rubber block then smooth with 180 or 240 grit wet & dry in soapy water.

Mask the area then apply 2 pack primer filler. (I only have a non-tanked compressor so I have to over thin it)'Guide coat' that and then flat off the repair with 400 paper again very wet. Stop/fill prime/guide coat the marks until you're satisfied, then flat the whole thing off with 600 grit or finer also wet & soapy.

Strip all the trim & lights off and get masking.

Find yourself a busy body shop who can spray more cars than he can prepare and slip yours into the queue. Around our way going rate is under 200 quid and you will be de-masking/ polishing the same day!

Sorry to rabbit but I love doing this although I wouldn't like to make a living at it!

Problem with those small orbitals is that it's easy to slip using one and if you touch the glass/rubber/trim the finished work will look crap, Don't think you can use wet paper on them and they can still show up small horseshoe shaped swirls in the finished paint due to sinking.

[crankedup]

Thanks for all that, I've dropped the idea of using a power sander and got myself a small pile of wet/dry dirrent grades.

[52classic]

Gosh.. Coach painting - Brilliant.

Did my mates F350 crew cab a few years ago and it still looks good.

Suggest brushing all the difficult bits first then use a radiator roller, best of luck!

[anonymous-user]

you may struggle to find a bodyshop that will paint a car for you that has already been prepped.
i wouldnt want to paint a car that has been prepped by someone who doesnt know how to.
if there are any imperfections or problems it will really complicate things

[Bigdick]

Wet flat all over with 1000's,thats what i always do and look at the results...sportmotive.com

Front end,normally pepperd with stone chips so 400's or even 240's if its realy bad,i always give a couple of coats of high build and knock it back with 800/1000's.

i find it works very well to do it with 1000's all over.

Hope this helps

Richie

[52classic]

Just collected my latest self prep project. A Renault Twingo, in a bright Magenta colour, destined for my daughter.

Very pleased with the results, will start to refit all the bits tomorrow,