Sticky ? Paint ,panel repair thread? Can we do bodywork experts please???

most bodyshops /pro's will dry sand these days

there is some chance of the primer taking on water , but its been done like that for years in the past , its more when the primered car is left out in damp weather that it will suffer

i mainly reccomended wet sanding as the papers are easier to get for the diy man , less clogging - simplest way for the home user to get good results with off the shelf stuff

random as it sounds the free cut papers for dry sanding have differant grades its roughly half ...so where you might wet sand with 800 - free c ut would be 400

 

I'm no painter, but for my little DIY projects, I've always dry sanded using the "wet sand" paper. Is that a dumb thing to do?

 

Also, when painting bare metal - like a new patent replacement wing. I sand down all the black primer it comes in, then use a 2 component "Washprimer". Is that the "etch primer" that you refereed to? I then use a high build polyester primer. The question is - do I scuff up the washprimer before applying polyester primer?

 

on a good quality new panel that black coating is good stuff and can be keyed then prime/painted over , cheaper pattern panels are often just cheap black primer and should be sanded off

sounds like your wash primer is indeed etch , no i wouldnt sand it just let it dry /flash off and then on with the primer

polyester primer isnt the correct stuff for a new panel , its extreme build stuff mainly for covering up bad repairs - polyester soaks up moisture badly too

if the sandpaper is working for you carry on..id imagine it clogs faster than the proper stuff

 

Yea, my replacement panel was made in Taiwan, so I'm guessing it's not good quality. Fitment was also poor. lol

What would be correct primer for a new panel? Etch primer and then epoxy primer perhaps, how many layers before sanding? The problem for me is that it's extremely easy to blow through the primer when block sanding for base color, that's why I used high build polyester primer.

 

etch or epoxy on the bare metal

then 2-3 coats of high build primer - 2 pack stuff will be much better build than the 1 pack /cellulose

bodyshops will also paint new panels in a method called wet on wet - basicly prime and paint in one hit without sanding in between , but you would need the pro style products not aerosol stuff

 

Great info, thanks man!

About rust repair - imagine a spot of surface rust, that's not too badly corroded and doesn't necessarily require cutting and welding in new metal. Say I grind down the rust or sand blast the spot. I then key the surface around it, hit it with etch primer, then high build primer (as body filler won't stick to etch primer), sand it smooth, then more primer, sand it smooth, then paint & clear. Is that a good technique?

The other way to do this to apply the filler straight on the bare cleaned metal. And then what?

 

yes thats fine ...etch then prime until the surface is perfect

or fill the clean pitted surface , light mist of etch then high build primer

 

Panel prepped ready for paint, sorry thought I had some earlier ones when I started



Painted! note I haven't blended in to the door! Didn't paint right to line so managed to blend ok



Still needs to be flatted and polished

 

I like the idea of zinc rich primers on removed rust, but it seems too thick to spray properly out of an aerosol and electrox is so high solvent if you milk it from the can and brush on. The second coat at 2hrs can just wipe through the first coat.

 

consider the jotun jotamastic epoxy ...its thick enough to fill pits and grinder marks etc and dries properly so no fear of it pickling up when you paint it

 

Evening mate.
I paint a lot of my own stuff with a gun 2k's , base/lacquer etc and some effects using stockings, candy's and metal flake. Done a beetle wizard with 25litre and a machine mart gun once lol
But there's something I was told about but have never tried. Priming or paintingsolid colours with a roller. Have you tried it, and what's the benefits or pros/cons?
I'd imagine for filler primer it could be great.
Any info would be great.

Another question as I'm coming to do it and haven't do d it for a while is plastic priming. I have done 1k plastic primer, do I use another primer on top or, can the top coat go straight on? ( I'm painting straight 2k red)
Thanks in advance

 

primer yeah it can work with a roller

ive messed around with rollering enamel top coats , you can do it with repeated flating and recoating , but youd be mad to do it if you have a compressor and somewhere to spray

plastic primer , either really give the plastic primer a tickle and paint , or if theres some defects in the part use some high build and sand it smooth

 

http://www.u-pol.co.uk/documents/datasheets/tds/GRIP4-TDS-EN.pdf

upol adhesion promotor , the claim you can paint say a door jamb or back of a bonnet with just panel wipe as prep , i would still scotch it but it can be handy to use as a added step for better grip

theres 2 pack versions avail for the pro's which are great too

 

Etch will stick to filler, but filler won't stick to etch? What kind of sorcery is this?

 

it might well stick ..its just the normal way is to fill over clean bare metal or epoxy primer