My Suzuki Cappuccino has had a hard winter tucked up in the garage and now I'm getting it out for the summer and I've found a pair of small rust bubbles near the rear arches. No problem, I thought. I've sanded it back a little and treated with rust converter and today I sprayed on some filler primer. It's a Halfords aerosol of the sort I use all the time - normally without a problem. This time, before the paint has even dried, cracks started to appear in the new paint. I've wiped it off and it has softened the 17 year old colour beneath. What do I need to do to clean the mess up so it takes the new paint?
The reason for the reaction is that the solvent/thinners in the primer has soaked through the original paint which then softens it and gets underneath and lifts it causing cracks/wrinkles, this is generally caused by putting the primer on too heavy. You will need to let the primer completely dry out then sand the area that has reacted untill smooth, then re-apply the primer in light coats to prevent the same thing happening again (a heatgun or hairdryer is also useful to speed the drying process between coats) just take your time and dont rush it, give it a good 20 mins to dry after each coat and it should be fine.
there is another possible cause as well you may find that the old paint is cellulose and the rattle can is synthetic, these two are awful for reacting
together, if the problem persists rub it right back and apply a coat of "barcoat" made by upol there are others about normally advertised as
isolators, since it is not the whole panel you are painting you will have to be careful with the top coat as well.
tilly
i've sprayed cellulose over halfords can primers plenty of times and its been fine? ^
Dry and warm the area up slighty, when using cans of paint I genneraly shake them as prescribed then place in a bowl of hot water, leve for 5 minutes than shake again and apply the pressure increases so make sure you keep a good distance away, Lighter coats are better andleave ample time to dry before next coats
quote:
Originally posted by blakep82
i've sprayed cellulose over halfords can primers plenty of times and its been fine? ^
quote:
Originally posted by tilly819
there is another possible cause as well you may find that the old paint is cellulose and the rattle can is synthetic, these two are awful for reacting together, if the problem persists rub it right back and apply a coat of "barcoat" made by upol there are others about normally advertised as isolators, since it is not the whole panel you are painting you will have to be careful with the top coat as well.
tilly
IME, tf it's the Halfords filler-type primer, it's very susceptible to ambient air temperature...want it as warm as you can...
Thanks everyone. I've been away for the weekend so its been sat in the garage for a few days to dry off. I've dry sanded it and put a very thin coat on. We'll see what it looks like tomorrow. Sadly, there's not much I can do about the ambient temperature. Does warming the can make a difference?