Isolator

[millerman]

Has anyone experience of using isolator when there is a reaction between the old paint and the new when being sprayed? Isolator is £13.62 per litre from the local paint factor and using this seems a lot easier than stripping back to bare metal.

Advice much appreciated from those that have used this product. I believe 2 pack primer will also act as an isolator but, unfortunately, I haven't the set up to use safely unless someone has a safe shortcut!!!!

[doobry]

unless someone has a safe shortcut!!!!

There's no 'safe' shortcuts with 2-pack. Some people are more tolerant to the poisons than others but are you 'dying' to find out?

[jonathon]

If you are attempting to paint over cellulose with 2K paint beware. If you have any body repairs ,i.e filler under the cellulose, when any 2K product is painted over it there is a high probability that the filler and paint will be re activated, resulting in sinks in the 2K surface, this resembles a fine crazed look in the shape of the repair. The best route to a good paint job is to fully remove the original cellulose layers and start agai with etch, primer and top coat.
Isolator coats can work but go for the best quality product on offer, cheap paint is not worth it. We had a GT6 in to respray and unfortunately I agreed to the owner supplying the paint. He bought 5 liters of base coat and 5 liters of laquer and associated thinner and activator fo £99. Needless to say the base coat reacted with the quality primer I had lavished on a well prepared shell. The car had to be re stripped to bare metal as both coats were rendered useless. The correct primer, base coat and laquer were applied , no problem ,lovely job. But good paint costs, you should budget at least £450 for paint if using a solid colour and more if using a base coat and laquer. There are no short cuts to a good paint finish, and always use the correct breathing equipment when spraying either cellulose or 2K, or it WILL kill you, or your neighbours.

[millerman]

I have no intention of spraying 2 pack! Although I have come across garages that spray 2 pack in an open workshop after everyone has gone home for the day,but they did use an air-fed mask.

Nevertheless the use of an isolator would appear to save work. I shall probably try some on one of the panels that have been removed from the Traveller then I can find out for myself!

I have purchased some Dupont Trafagar blue basecoat/laquer, the basecoat was mixed using the appropriate colour code. Previousley I've used International paints Snowberry white acrylic paint on my saloon which proved ok and still polishes up to a reasonable shine.

Thanks for replies

[chickenjohn]

It sounds like it might be easier to paint the car in cellulose!

Just an idea

[plastic_orange]

I've used isolator when things went wrong, particularly when trying to rectify someone elses bodge job. Sometimes you don't know what the paint quality is that you're spraying over, so flat it back, strain the isolator through a strainer, then spray as per instructions. Do not flat back, but spray primer on top, then flat back and spray top coat - watch you don't go through isolator coat though!!.
I've done loads of motor bike spraying, and one time could not figure out why I was getting a reaction when I took over a poorly completed job. Turned out that the 'professional sprayer' had not used sufficient hardener in paint, and it kept being reactivated by the new paint. I flatted it all back, sprayed isolater on, then primer, flatted it back and then top coated - all in 2k.
Bike still looks good after 6 years in all weathers.
I'm not a professional sprayer, and just do it in my garage - no complaints so far. Don't really do much now though, but have 2 minors to spray soon. 2k is quite easy to spray, but cellulose is easier, but you can get shrinkage at repairs. If done properly neither really needs cut back as the job should be gleaming when you finish, but compounding will take out any dust marks and provide a good base for the polish. Must admit though, the paint supplied now is not as good as it used to be a few years ago!!