How much primer & paint

[pskipper]

Okay, we are rapidly approaching the point in Rosie's restoration where we'll be stripping her down and respraying her. Because of the appalling paint job a previous owner did we are taking her back to bare metal and starting again.

From what I've read we are going to need between 5-7 litres of topcoat/colour paint to do the whole car, my main question is how much etch primer and high build primer will we need and will we need an equal volume of thinners?

Thanks,

Philip

p.s. a sticky with paint volumes for a full bare metal respray would be really useful.

[tysonn]

Cellulose or 2 pack?

[pskipper]

Cellulose, we don't have the space to put in an external compressor for the fresh air feed you need for 2 pack.

[bmcecosse]

That's an awful lot of top coat - I would think 3 litres is plenty - and same mount of primer.

[les]

I'm surprised you think that Roy, I bought 10 litres, admittedly to make sure of things, I'm glad I did as I've got about 2 litres left and still need to do the bonnet and rear doors. I have done inside and out and wheels, (that may have been a mistake!) It's a van so maybe more area but still think 3 litres is a bit lean even for a saloon. Don't forget it's also nice to have some in reserve for future touch-ups. All from the same mix avoids colour match.

[bmcecosse]

I sprayed my Trav with 2 litres - and still a good lot left over - can't say how much really because it has thinners in. And the Trav has big glass area - hence my estimate of 3 litres.

[kennatt]

8 litres makes up to 16 when thinned. wow how many coats did you put on you do know that if you make the top coat too thick that after a few years with the constant contraction and expansion in the sun that too thick top coats start to crack,hope not in your case three litres of cop coat thinned to six should be more than enough to do a moggy van or otherwise.

[tysonn]

Back in the dark ages when I used cellulose I always made the top coat about 80% thinner.You have to be careful but it means less refinishing.I reckon 4 litres before thinning will be right.Thats it with celly you HAVE to put plenty of coats on to get any depth.Thinned 50/50 thats 8 litres but you dont get 8 litres on the car,a large proportion of it evaporates into the air as you spray.If you Google for " Gerson" they do sub £20 masks that are ok for 2 pack(cringes in anticipation of the comments).

[les]

Well if you start from scratch I would say there is as much painting required on the inside as outside when you think about it --doors, cab, cargo area(van) engine bay, (in my case wheels), roof inside, cab floor, cargo floor, fittings etc it all mounts up, will admit sprayed roof twice as it got marked. The panels are well covered but not to excess, to my way of thinking, however you don't want to see the primer after the first polish and don't forget unless all this work is done in one hit, not easy with limited space, there is a certain amount of 'waste' cleaning the pot etc after each spraying session. I have actually done this work so not speaking from theory. I use just thinner than a 60/40mix to start then reduce somewhat. I have 2 litres over to do the rear doors and outside of the bonnet.--------or by some estimates another car!

[tysonn]

Les in your case I bet you did use all that.I was just meaning the usual outside/door and bonnet and boot shuts etc.
Mick

[pskipper]

As I said in the original post it will be the whole car, maybe I should have added 'inside and out' as well to be more clear. I was going to go for 5 litres so that I would have some correct colour matched for touch ups and chip repairs. So Roy just said the same amount of primer, how does that break down into etch primer and high build? Last thing I want to do it run out and risk losing a spell of good weather!

[les]

You will only need the etch primer if you go to bare metal, inside you will probably only be rubbing down factory finish, in fact on the outside some people only rub down to factory paint, me included, so unless you break through to any significant amount or intend a bare metal respray I doubt if you need etch, If you do, it's put on thin. I'd buy 5 litres of Primer for a car. Wait for other replies and take the average, opinions differ on method and quantity!

[pskipper]

We were going to go down to bare metal, not sure what the previous owner sprayed with but it's reacted with the original paint

[les]

Not so good then but good luck.Someone had hand painted the inside of mine with household paint, takes all sorts I suppose!

[pskipper]

My wife's car (Betsy Belle in the picture) had (and still has I suppose) the headlining and sun visors painted in white matt ceiling paint by the last restorer

[chickenjohn]

Back in the dark ages when I used cellulose I always made the top coat about 80% thinner.You have to be careful but it means less refinishing.I reckon 4 litres before thinning will be right.Thats it with celly you HAVE to put plenty of coats on to get any depth.Thinned 50/50 thats 8 litres but you dont get 8 litres on the car,a large proportion of it evaporates into the air as you spray.If you Google for " Gerson" they do sub £20 masks that are ok for 2 pack(cringes in anticipation of the comments).

I agree apart from the 2-pack mask. No one should use 2-K without an air fed mask and an extracted booth if they value their life!

As for quantities,:-

5L of top coat to do the whole car inside and out, 5L of top gloss thinners, 5L of high build primer. 1 l of etch primer (you only need a thin coat!) and about 10L at least of standard thinners as you will need plenty for gun washing etc. And I often find that with my spray gun that I need to thin celly high build primer more than 50/50 to get it to spray well as a nice wet coat.

An experienced pro may get away with less materials but the less experienced will need at least five coats of cellulose top coat ( thin "gripper" coat, three full wet coats and a final coat thinned 75% with thinners) to allow plenty of film build for wet sanding to remove any orange peel and runs.

I also like to apply four coats of primer, dust with a black guide coat then sand with 400 grit, then four more wetter coats of primer, and guide coat again sand with 600 or 800 grit. When your primer is free of guide coat specks and almost shines it is so smooth with no scratches, pin holes or imperfections then you are ready for top coat.

If any areas need filling, I personally etch prime then fill and sand and etch prime any bare metal again. If you dust the etch over the filler, it seems to stop sinkage of primer into the filler.

[pskipper]

Thanks, that's a great brief guide and a good tip about etch primer over filler. I'd not heard of that before!

[chickenjohn]

I also use 1K stopper to fill any imperfections visible after the first primer layers go on- scratches, filler pin holes etc, then sand the stopper smooth with 400 grit and prime again a few times.

Always dry sand filler and primer- you don't want water being absorbed in your filler or primer layers, to avoid paper clog, either use an Abranet /Mirka vacuum sanding system or (wearing a dust mask!) use a blow gun with your compressor to blow the dust off the panel and paper. Always sand with a block (unless the panel is tightly curved in that spot).

Oh, you will also need a few litres of panel wipe and some tack cloths. Use panel wipe to clean the panel before etch priming, before filler and before any layer of paint, and especially before top coat. And remove the car from your work space before applying top coats and sweep/ vacuum up all the sanding dust and just before the first top coat go over the panels with a tack rag to remove dust.

[les]

In reality how important is it to use wet&dry paper dry rather than wet? I ask because I've always used the latter over the years even rinsing off before letting dry, with no ill effects, obviously not covering with top coat immediately. Maybe times change but it used to be the accepted way.

[chickenjohn]

Les, certainly when sanding filler always sand dry! and there is always the risk of sanding one bit of primer down to bare metal. So I would not want water anywhere near that either.

If you use the Mirka Abranet system, with velcro perforated abrasive sheets and a vacuum hose to remove the dust, the paper does not clog. I learned paint prep on the Vehicle body restoration course at Mid- Kent college (still go in to use the equiment there as an Advanced student on my own projects) and they teach dry sanding of filler and primer with the vacuum system.

http://art.mirka.co.uk/ The sanding block, hose and papers are available from screwfix and all good auto paint suppliers.

Wet, colour sanding is for 1200, 1500, 2000, 3000 grit paper on the cured top coat to remove dust specs, and orange peel etc.