Why is my painting always ****

I am in the process of painting my chequer plate body coloured to try and hide it a bit (don’t want to get rid of it as I like to throw my tools on top of the wings when I am working on it)
My process was

1. Wire brush and scotch bright pad them to scuff up the surface.
2. Use panel wipe to degrease
3. Spray with 2 coats acid etch
4. Spray 3 coats Oslo blue
5. Paint 2 coats clear lacquer

I have left it to cure for 48 hours and when fitting if I so much as touch it with anything other than my finger it scratched down to base, even tried putting low tac masking tape on to protect it and it bloody ripped the paint off! I am obviously doing something wrong but what am I missing?

Not an expert on paint but is that the recommended process for your acid etch? I thought you usually only need one coat of acid etch and for some types you need to coat over it when it is still tacky.

Also curing for 48hours might not be enough if it's just left out in the. It can take a number of days to fully cure depend on temperature.

The answer to your problem is epoxy primer.

I spray stuff for work so have guns etc. but i guess you could probably brush paint it also.

I always use tins of paint and rollers rather than spraying but if it is an enamel topcoat then 48h is a minimum, potential needs much longer especially with the temperature recently having cooled down.

But based on your description the issue is the acid etc not actually binding to the surface correctly. A lot of them are water based so it needs to be perfectly degreased and dry.

On bare alloy you need acid etch wash which is yellow and just gives a covering then a primer then top coats leaving correct hardening times between coats and then takes a couple of weeks to harden fully...

Do you have to mix hardener with your paint? If so maybe try putting a lot less in.

I've painted quite a few old tractors and parts with pretty good success. Sounds like your prep is right. I usually use the air gun to blow dust away, then degrease spraying onto a rag then wiping - don't spray onto the metal then wipe.

I've never used acid etch so I give a couple of coats of primer waiting until it's just tacky between coats. The first primer coat should be a light mist hardly visible. Then I leave it as long as possible before doing anything else, anything up to three weeks.

Before putting the topcoat on I give it a very light going over with something around 1500 grit sandpaper then wipe. First coat of topcoat should be a tac coat nothing more than a fine mist. Then a normal coat or two followed by the final one. If you want a shine put the last coat on as wet as you can without it running.

You can go further like finely sanding between top coats etc but I don't think it's necessary on chequerplate as you're not looking for limo standards.

I've usually painted in the summer in a tin shed so it's been nice and warm, can you maybe get some heat into where's you're doing it?

Just my process incase it's helpful

NewbieWithA90 said:

Do you have to mix hardener with your paint? If so maybe try putting a lot less in.

I've painted quite a few old tractors and parts with pretty good success. Sounds like your prep is right. I usually use the air gun to blow dust away, then degrease spraying onto a rag then wiping - don't spray onto the metal then wipe.

I've never used acid etch so I give a couple of coats of primer waiting until it's just tacky between coats. The first primer coat should be a light mist hardly visible. Then I leave it as long as possible before doing anything else, anything up to three weeks.

Before putting the topcoat on I give it a very light going over with something around 1500 grit sandpaper then wipe. First coat of topcoat should be a tac coat nothing more than a fine mist. Then a normal coat or two followed by the final one. If you want a shine put the last coat on as wet as you can without it running.

You can go further like finely sanding between top coats etc but I don't think it's necessary on chequerplate as you're not looking for limo standards.

I've usually painted in the summer in a tin shed so it's been nice and warm, can you maybe get some heat into where's you're doing it?

Just my process incase it's helpful

Click to expand...

Thanks for that, I have left the last 2 pieces for a couple of weeks now and the paint seems to be a bit harder to scrape off so maybe just needed to leave it longer, all the bits I am painting just now are small so I am just buying spray cans for everything, painting in a metal shed so it is quite warm

Some paints like rustoleum spray cans do take ages to fully set. I remember doing an old Suffolk Punch lawnmower and their paint took a couple of months before it was hardened and unaffected by fuel.