Classic cars forum & vehicle restoration.

[rcx822]

I've read the book "How to paint your car" by Dennis Parks. I just want to check I've understood it all.

I'm painting a little 4x4 which does get used off road, and collects dents and scratches, so a perfect paint job is not needed. I just need the couple of "new" used panels to match the colour of the rest of the car.

Essentially, in my case:

Any areas of rust remove rust with 80-100 grit
Apply epoxy-primer to any bare metal
500 - 600 grit to scuff the existing factory paint (car is early nineties)
Apply sealer layer
Load paint gun, tack off, then paint
Gun 6-8" from surface, perpendicular, spray with 50% overlap on each pass.

Does that sound about right?

I'm wondering if it's worth using a two stage paint, ie colour and clear coat. Considering my use, and that 100% colour match isn't important on a rugged looking vehicle, maybe one stage is fine?

Also, whats a decent paint-system/brand to go for? And any paint supply shops in the London area that are recommended?

I have a 3HP compressor and paint gun I got off a friend, non HVLP. I've got a heated garage. I can measure the humidity. Maybe rent a dehumidifier?

Tools needed, anything to add to the list?

Filter/water trap on compressor
Paint gun
Lots of dust sheets
Paint stirers
Filter to fill up paint gun
Tack off cloth
Paper to test gun
Spare body panels to practice on

[kevin2306]

Id say you need to add panel wipe and an air fed mask to your list. the compressor needs to have a fresh air supply otherwise its recycling the air that is loaded with paint spray.
Cant comment on the type of paint as I have only used cellulose.

Have you considered brush painting? if its an offroader and gets damaged, that way its easier to touch up

Kev

[Ray White]

I agree with Kevin. If you are doing any painting yourself, only use nitro cellulose. Also get 'top gloss' thinners not gun wash.

I would leave 2 pack to the professionals. It's not worth taking risks with your health.

You need to consider that the air coming out of your compressor is wet and oily (unless it is an oil free one) so you will need moisture and oil filters to avoid blistering etc. You could also benefit from a cheap disposable in line air dryer.(Ebay?). None of these things are particularly expensive but will help you get a satisfactory finish.

Yes a de humidifier would be helpful but I would prefer to choose a mild dry day and ensure plenty of ventilation.

[Rootes75]

What is tacking off? Have heard people talk about it but not had it explained. I am about to start spraying with cellulose and it would be handy to have advise on the various stages.

[rcx822]

[Ray White]

Yes tack cloths are good for making sure there are no stray hairs, dust etc, but don't forget to get some 'panel wipe' to remove any finger marks/greasy spots etc.before tacking off.

Even your breath can ruin a paint job! So can sweat from your brow!

Don't worry too much if it's just an off road vehicle - the paint only needs to protect the metal from corrosion.

[colwyn500]

Tack cloths are really cheap, even from Halfords
They have a very slightly sticky feeling that doesn't upset the paint.
Once everything is a smooth as possible you thoroughly wipe everything with panel wipe (an alcohol based solvent which won't hurt paint) as much as your patience allows. Then blow out the dust and dried smears of primer Just before you start the topcoat you go over the whole car with a couple of the tack cloths. They are packed in a sealed bag and are ready folded so that you can regularly change the face that you are using to avoid re-contamination of the surface. It removes tiny fragments and particles which you might not see but the cellulose topcoat will show.

I suggest using disposable nitrile gloves at all these later stages as Ray White says,as much to protect the paint from body oils and sweat as to protect your skin.

I put on three generous coats of cellulose over the primer, which was prepared with 320 to 400 grit paper left it a week and then went over the topcoat with 600 wet and dry. After more prep as above I used a final three coats of topcoat which had been thinned a bit more than standard 50% and used very good thinners.

A couple of weeks late I used Farecla cutting compound to enhance the shine followed by wax polish.

People will suggest finer grits of paper, more or less coats of paint, flatting the paint with extremely fine paper before cutting and waiting for longer or shorter periods before each stage. The above system worked well for me.

Also WAIT FOR WARMER WEATHER. By that I mean when the outside temperatures have settled into at least double figures. Choose a still day, prepare the garage the day before by sweeping and damping down lightly.
http://www.oldclassiccar.co.uk/forum/phpbb/phpBB2/viewtopic.php?t=13107&postdays=0&postorder=asc&start=705

[rcx822]

Thanks for all the tips.

Cellulose paints were not mentioned in my book (which claims to be updated). So cellulose is a type of paint? What's it's advantages?

Colwyn, did I understand correctly that you use 320-400 grit to prep the surface before painting? And is this on top of factory paint?

Does cellulose use a final clear layer?

Regarding warm weather, my garage is heated, so I don't need to wait unless there's more too it.

Regarding suggestions to use brush on paints because my car is abused, it does sound like a good idea. But the bonnet is very pretty, and the rear bumper (plastic) is also quite slick as I modified it. It's pride... plus I like to learn, so I will consider brush paint, but might still use a decent spray paint.

[colwyn500]

[rcx822]

[Ray White]

Basically, nitro-cellulose has been banned by the EU on environmental grounds, although there are exceptions for classic cars and only it's only available from specialist suppliers now.

Personally, I would not touch modern paints for D.I.Y. because they are toxic and require an air fed mask.

I can only give my opinion, but you may also be in breach of certain laws regarding 'health and safety.'
Essentially, you should only use 2 pack in a dedicated spray booth with all the approved equipment and be qualified in the handling of hazardous materials.

I may be wrong about this but I wouldn't like to take the risk.

[colwyn500]

I fully endorse what Ray says.

When I bought my cellulose paint I had to state which year and model it was for and therefore I had to choose a code from the range of colours which would have been available in 1969. No problem to me as that's what I wanted. It would be an issue if you needed an exact modern shade.

PS. Back to the original question; you would degrease the original (sound) paint before and after sanding and ideally, go over with a tack rag before priming.

[ukdave2002]

I've painted a few car so to add my two penneth:

add a filter to the air inlet on the gun, they are only cheap and trap any moisture that forms in the airline.

Dirt and moisture are the worst problems in the home workshop; don't paint on cold damp days, go round the workshop with an airline and blast as much dust as you can from all the nooks and crannies.

Don't paint in primer and then leave it for a few days (unless its epoxy primer), the primer will absorb moisture resulting in micro blistering in weeks / months to come.

Add some phosphoric acid to your list, coat any bare steel with it, then clean with panel wipe, then wipe with a tack rag.

Try spray so that the paint is just about to run, you may need to play around with the amount of thinners on a test.

Finally runs and orange peel can be corrected when the paint is dry, don't worry if you get them, pro's do to all the time!

Dave

[Phil - Nottingham]

Good tips - cellulose is great. I get mine and have done for 20 years odd from Sprayguns Direct of Morleys Derby - though I call in and get it. They mix up to exact shade too
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