painting using aerosols

[retromadness123]

Hello guys right just need some help I'm trying to spray some imperfections on my car using a color matching aerosols, I am taking back the little bubble rust, applying filler, sanding it down with 60/80/120/360 grit then applying primer and sanding it back with 800 before the main coat, now I'm no expert but I'm sure there must be more I could do to make the finishing better, I am aware a spray gun and all that would be better but I'm on a tight budget at the moment so its aerosols for me at the moment but want to see if I can get the best finish from it all help is appreciated or if someone can point me in the right direction for any videos or write ups that I can check out will be good to thanks again for any help on advance

[avengertec]

Make sure you do it in the summer

[SmokeEm]

plenty of thin coats of paint and once properly hardened (at least 1 week) then a final rub with 1200 grit wet n dry (With plenty of water) - Then cut back with a bit of mild cutting compound followed by a polish.

[scott15]

Just to make you aware the rust will come back after a short while, as really you need to be removing the rust from the panel, not just knocking it back.

Anyway..

Firstly, you need to feather out the paint around the area, otherwise you will be left with the outline of the existing paint around your repair. I do this using a DA sander with around 320 grit on it. However you could also do this by hand. You are looking for a smooth finish between existing paint layers and the body metal.

Skip the 60 grit - go straight in with 80, if you don't have a block to sand with, now is the time to invest in one. 80 grit is coarse enough that you will be cutting the filler (not smoothing it like lighter grits).

Get your filler to the shape you need with the 80 grit. This may involve more than one spread of filler.

Once you're very close to the desired shape, you should be going in with 120 grit. Using the 120 grit to remove all the sanding marks from the filler and surrounding paint work from the 80grit.

From here I would spray a layer of primer over your work, this layer will help you see anything uneven in your work. Spray some guide cost on this layer (coloured spray paint misted over the top of the primer) and start sanding with 240 grit. You will start knocking the top off the filler. If you see any patches of coloured paint, these are low spots and will be visible when you do your final spray. Best to go back with another layer of filler at this point and start from the 80 grit stage again.

If there are no low spots here. Then carry on with the 240, you will find that the primer will now be sat in the scratches left by the 120 grit. You want to get rid of all of these (and the surrounding area) with the 240.

Next you'll be wanting 400 grit. Again, as you are asking about how to do this, i'd go with cover in primer again and knock down to the point you have no 240 grit scratches. Once you've done this a lot you will be able to work out when you've got rid of all your previous grit scratches without keep spraying the primer. But for now it get's rid of the guesswork, so i'd go with it.

Then same again with 600 grit. Now, once you've finished it in 600, spray primer over your work again, guide coat this layer as well.

Now by this stage if you had a spray gun, you'd just finish the primer in 600 grit, and be ready for spraying. However with aerosol you will find it is much thinner. I would block the primer and guide coat down with 800 grit. You arent looking to go through the primer, you are wanting to keep the primer this time.

Sand with your 800 grit till you have removed all of your guide coat. Once there is no guide coat left, you will see (and can feel) your primer is flat. Really flat. This is the perfect base for you to then spray your colour coat.


Although this is a very long process, this is the only way to get a decent result with aerosol. Make sure you definitely remove each layer of grit scratches with the following grit sandpaper. Otherwise you will have nasty scraches under your nice shiny paint.

Enjoy!

[retromadness123]

Very good explanation Scott, I'm working on it and I have had some good results but as you mentioned I can see scratches on my shiney paint, also Defo need to do it in summer but I needed the car ready before Xmas as it looked a mess and wanted it looking nice and not a rusty bucket when the guests arrived, first I warmed the can in hot water but it got cold soon as I began spraying so out came the missus GHD hair dryer to warm the panel before spraying and luckily didn't make the paint run lol boy it did help lol don't tell her tho

[ChasR]

Is it metallic or solid?

I've done solids before with good success using a similar procedure to the above. You couldn't tell it had been done.

I've not seen metallics done so well but you do wonder if that is down to the prepwork.

[retromadness123]

Its solid think its mostly prep that makes it a good or bad job and these days with so many different products its so much easier to work on the body and get a good finish

[retromadness123]

Nov 30, 2017 9:35:38 GMT scott15 said:

Just to make you aware the rust will come back after a short while, as really you need to be removing the rust from the panel, not just knocking it back.

Anyway..

Firstly, you need to feather out the paint around the area, otherwise you will be left with the outline of the existing paint around your repair. I do this using a DA sander with around 320 grit on it. However you could also do this by hand. You are looking for a smooth finish between existing paint layers and the body metal.

Skip the 60 grit - go straight in with 80, if you don't have a block to sand with, now is the time to invest in one. 80 grit is coarse enough that you will be cutting the filler (not smoothing it like lighter grits).

Get your filler to the shape you need with the 80 grit. This may involve more than one spread of filler.

Once you're very close to the desired shape, you should be going in with 120 grit. Using the 120 grit to remove all the sanding marks from the filler and surrounding paint work from the 80grit.

From here I would spray a layer of primer over your work, this layer will help you see anything uneven in your work. Spray some guide cost on this layer (coloured spray paint misted over the top of the primer) and start sanding with 240 grit. You will start knocking the top off the filler. If you see any patches of coloured paint, these are low spots and will be visible when you do your final spray. Best to go back with another layer of filler at this point and start from the 80 grit stage again.

If there are no low spots here. Then carry on with the 240, you will find that the primer will now be sat in the scratches left by the 120 grit. You want to get rid of all of these (and the surrounding area) with the 240.

Next you'll be wanting 400 grit. Again, as you are asking about how to do this, i'd go with cover in primer again and knock down to the point you have no 240 grit scratches. Once you've done this a lot you will be able to work out when you've got rid of all your previous grit scratches without keep spraying the primer. But for now it get's rid of the guesswork, so i'd go with it.

Then same again with 600 grit. Now, once you've finished it in 600, spray primer over your work again, guide coat this layer as well.

Now by this stage if you had a spray gun, you'd just finish the primer in 600 grit, and be ready for spraying. However with aerosol you will find it is much thinner. I would block the primer and guide coat down with 800 grit. You arent looking to go through the primer, you are wanting to keep the primer this time.

Sand with your 800 grit till you have removed all of your guide coat. Once there is no guide coat left, you will see (and can feel) your primer is flat. Really flat. This is the perfect base for you to then spray your colour coat.


Although this is a very long process, this is the only way to get a decent result with aerosol. Make sure you definitely remove each layer of grit scratches with the following grit sandpaper. Otherwise you will have nasty scraches under your nice shiny paint.

Enjoy!

Is it best if I sand it wet or sand it dry when I use the different grades, thanks

[igor]

I have found this to be a very good product.




It goes on fairly thick with good coverage in few coats and does not run appreciably unless one does a very bad job of spraying it.
Their International Harvester red is an almost perfect match for my car too which is a bonus.

[igor]

That picture is much larger than I anticipated it would be.

[retromadness123]

I see where can i get that from ?

[igor]

I bought it from our local hardware store for $NZ18 per can. I believe it is an American product.I expect it will be available it the UK somewhere.

[scott15]

Is it best if I sand it wet or sand it dry when I use the different grades, thanks

This is where different people have different opinions.

I personally never wet sand primer. Primer is porous. Spray a bare metal panel in primer, then leave it out in the rain, after a while it'll go rusty. I certainly wouldn't want to risk it, however that's not to say that wet sanding shouldn't be done, as I know a lot of people do exactly that.

Really I'd say it's up to you. I only wet sand the clear coat before polishing. At the primer stage I sand dry, any dust is thoroughly cleaned off with the panel wipes.

Just as an FYI, if you have haven't got panel wipes or degreaser sorted yet.. You can buy wet wipes that come in a ltitle tub/bag, or you can buy a can of degreaser and use blue roll or kitchen roll etc.
Best way to degrease is to wipe on wipe off. So go at it with your wet wipe, then follow it behind with a nice dry clean rag/kitchen roll or whatever. Don't let the degreaser dry on the panel, you'll notice a dust trail if you do this.
Feel free to go over as many times as you like, it'd be a pain to ruin the paintwork with a few specs of dust left after sanding.

[retromadness123]

Thanks scott, i orderd my sand papers and also got a sanding block and a electric sanding detail mouse, also if the paintshop made the aerosole with laquare, is it ok to still add a clear layer on top, and when you wet sand the clear coat what grades of paper do you use and what sort of polish do you use, and i heard people talk about compounding,where would you compound, thanks for the help juat want to try getting the best results