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what have I done wrong??

Posted: Sat Dec 30, 2006 5:45 pm
by melj
Hi there. I suspect I know the answer to this but am deeply frustrated.

I have been dealing with some small rust bubbles along the tops of my front wings, and thought I had prepped everything adequately but have just now attempted the final aerosol of brown paint and the primered patches have puckered up round the edges. Thankfully only tried 2 small patches but am now left with a load of primered bits which could be useless to me!

I sanded off the areas I wanted down to steel and put two coats of red oxide primer on, letting each dry overnight and with a fine sand after each.

My thoughts - insufficient sanding where primer lapped over onto original paintwork so no decent key - missing out a de-greasing or t-cutting step at the start.

Is this redeemable or will the whole lot have to come off and start again? What a waste of work - you learn the hard way!

Ta
Mel

Posted: Sat Dec 30, 2006 6:05 pm
by DoloWIGHTY
Sounds as though you might have had some damp in there and this is a reaction against it. Difficult to say without seeing but must be incredibly frustrating for you.

Posted: Sat Dec 30, 2006 6:33 pm
by melj
It looks like the skin you get on warm milk when it's cooling down, sort of ridged and puckered, lifting away from the body, and was an almost instantaneous reaction as the aerosol went on. Could be damp I guess, been in the garage at my folks but it's unheated and there was very light condensation on the chrome this morning. If it is damp, will a bit of light heating before the final coat do the trick or is it still a strip-it-all-back-and-start-again job?

Posted: Sat Dec 30, 2006 6:43 pm
by 1300dolly
could be dampness,there is no point in trying to spray paint this time of year unless you are in a sealed heated booth. even if the garage is warm you are still going to get dampness in the air.

Posted: Sat Dec 30, 2006 7:44 pm
by ALGIK
u need some etch primer and a bit less damp

Posted: Sat Dec 30, 2006 8:05 pm
by Nathan Mwk 627G
The only thing i would suggest is to take the lot off and do everything again up untill the primer, then heat up (could use a powerfull hairdryer) the area untill its near hot to the touch then spray/brush the primer on!! ( Also try warming the paint up in a bowl of warm 2 hot water untill the can is warm to the touch if primering with an aerosol)

As justyn says there is no point in painting in this weather as the paint will Oxidise almost stright away ruining all your prep work again, just leave it with the primer on but remember that red Oxide primer is porous so it will still rust.....spray Clear Lacquer on it to seal it over the winter months....

If the Primer on your wings has started to lift then effectivley you now have bare steal underneath which has no protection from the damp/wet so i would do it asap befor the car is driven!!

Again to quote justyn if you dont have a warm dry place to work, i wouldnt try and do any bodywork...im in the same situation and dont do any bodywork untill the weather is nice and warm!! When i bought my car in May i did all the bodywork in the first 2months!

Good luck matey!

Ps dont start by T-cutting as thats just adding crap to the surface just keep sanding as that removes a % of the grease etc!

Posted: Sun Dec 31, 2006 4:03 pm
by melj
Darn it! Here's me thinking to take advantage of the hols and a garage and put a stop to my rust and may just have made it all worse! Ho hum. Thanks for tips and advice, wouldn't have known about the need for clear lacquer that's for sure, and will leave it as it is until the summer now! And keep my fingers crossed that it doesn't all just rust through again!

Posted: Sun Dec 31, 2006 7:46 pm
by Purplebargeken
All the above tips are spot on. I also use a good rust killer such as Bilt-Humber, plus the red oxide primer, etc, etc, etc.

Just do what you can and be prepared to repeat the job in warmer weather.

Ken

Posted: Wed Jan 03, 2007 1:14 am
by 2F45T4U
Well bugger! My cars primer which has been on it some 6 or so months is rusting through (surface rust that you can scrape off with a finger nail but its ugly!) and I planned to paint the car soon. My car has to be painted all yellow by Feb for road rally regulations...

Sand it back, re-primer and just rattle can it inca yellow until the summer comes. Sound like a half decent idea?

Posted: Wed Jan 03, 2007 3:30 am
by 1300dolly
as said before its pointless painting in this weather even more so with rattle cans as they hold moisure within the cans.
do it properly the first time and it will last for years.

Posted: Wed Jan 03, 2007 10:20 am
by tinweevil
Sand it back, re-primer and just rattle can it inca yellow until the summer comes. Sound like a half decent idea?
Half decent yes provided you do re-do it in the summer. You will seal moisture in at this time of year. DO NOT use ordinary primer especially from a rattle can on bare metal. You may as well prime metalwork with old dish water for all the good it does protection wise. Go to any vehicle paint suppliers and ask for a tin of high zinc primer such as Bonda. It claims to be waterproof, it certainly is very very very water resistant. I've seen metal painted in nothing else survive two winters outside.

Warm the metalwork to dry it, wipe it down with thinners and the apply the Bonda. What you do beyond that is just decorative and will trap moisture so use whatever.

Tinweevil

Agree totally...

Posted: Thu Jan 04, 2007 12:05 am
by Jon Tilson
with tin except that Ive seen bonda primer disaear from all my usual stockists so Ive had to use Finnagins No1 which isnt too bad...

Jonners