10 replies to this topic

[Will]

I was just wondering about a few things that im not quite sure on.

Say im spraying the inside of my car myself like floors, back seet, parcel shelf etc., what sort of prep work is involved? Do i sand right back to bare metal or if its in good nick do i just give it a hey with sandpaper (if so, what grade?), and then what primer (would zinc be alright) and just any other pointers for painting the floor etc.

Any help would be great!

[Will]

Anybody?

[cooper_shaz]

Hey

For the floors/interior, if the paint is good and you have no rust then just key the paint.

If the metal is rusted then sand through to clean metal, if you want the paint to last you need to have that metal spotless, and little bits of rust in the metal will come back through.

Once you are at bare metal treat it with POR15 metal ready you get it from frost
clicky

This stuff is great, it will dissolve any bits of rust left and zinc coat the metal.
This makes the metal last much much longer

Zinc based primer is the way to go, it is meant for spraying over bare metal,
but unless it is in direct contact with bare metal it will have no effect, In which case normal primer will do if the surface is well keyed, or etch primer will be better as it bites into the surface below.

If you are spraying the same colour and you have no rusty bits you do not need to prime it, but make sure that you have no shiny bits left once you have keyed it and it is dry. Paint will eventually flake if you spray over shiny paint.

With regards to keying the surface it depends on what paint you are using and how you are painting (spray can or compressor)

Spray can - use a fine grade wet and dry to key P800 with plenty water and washing liquid in it (this stops the paper clogging)

compressor you can use P600 wet and dry as the spray gun will apply paint thicker and hide the fine sand lines.

For metalics use the finer paper as the metalic base coat goes on thinner and you will see sand lines through laquer.

If you are going to prime it all, then you can use p400 to key it, then prime it, then flat with P600 or P800 depending on what paint you are using.

Of course this all depends on how passionate you are about your car..

Bearing in mind most of the surfaces we are talking about will be under the carpet and not be seen.. just adapt the above to your desired level of finish.

[Will]

Cheers!

[Snowfruit]

Doesa allt hat keying and priming advice also apply to prepping the outside of the car for a respray?

[Will]

Can you filler over the self etch primer? or would you do it after the metal ready?

[cooper_shaz]

Yip the keying and prepping is the same for outside the car.. but use a finer wet and dry the higher the number the finer it is.

You can fill over etch primer, but the way i would do it is to get rid of the rust, then hit it with metal ready.

then fill the surface and get it up to spec, then etch prime.

after that deal with any minor imperfections in the filler using top stop ( search on google) it is a super fine filler..

hope this helps

[Will]

Thats cool, this is for my doors really. So the plan of action is get rid of rust, metal ready, filler, then top stop, then high build primer. sanding each surface as i go.

[cooper_shaz]

Yip, You got it...

When you are sanding your doors, here is a tip for a smoooooooth finish.

Get a bit of 2 inch wide and 1 inch high timber...

about 8 inches long...

attach a couple bits to it at right angles... almost like making a rectangle..
bit with 1 long side missing..


buy roll of sand paper and cover the wood and use this to sand the door

this will help give you a smooth finish and not end up with the ripple affect you see in alot of doors after they have been sanded with a small block sander as the longer piece of wood will sand level

when sanding the main surface hold the sander at an angle of 45 degrees and sand in one direction at a time in straight lines..

sand left to right, then up and down then angled (star shape) always lolding the sanding block at 45 degrees to the direction you are going in.

you are better to fill in very thin layers and a quick sand..

4 thin layers are better than 1 thick because you will get sick of sanding down thick layers and this is where the finish will suffer..

For initial ROUGH sanding of filler...use 40 grit paper..

[PikeyMini]

That is a very very handy post there mate, will let you know how i get on!

Cheers
Matt

[mini-mad-dan]

maybee this should be FAQ'd