Water Marks in New Saffron Spray Job

[Mark B]

Hi all

I have been spraying my Vitesse using Saffron Nitro Acrylic paint. So far front, rear, side valence's as well as boot lid and head light surrounds. After several days I left the boot lid outside overnight and it rained. The droplets soon evaporated by the following hot day. This left white marks on the surface that I wiped away with a damp cloth. Looking closely there were outĺines of the water droplets etched in the surface paint film which needed T-cut to remove. I thought the paint was still drying out but after six weeks if I spray the painted items with either rain or tap water and leave in direct sunlight I am left with the same marks.

I spoke to the supplyers who were very helpful and mixed me some new paint just to rule it out. Still had the same problem.

I decided to buy some nitro cellulose from another supplier just to rule out the paint. Unfortunately I am still getting water etched marks on the paint, not as bad as the first lot but still there, if you catch the light just right.

The second lot of paint has only been on the metal test cards for a few days so it may be to early to subject it to water and sun.

Both paints are branded quality from reputable suppliers.

I am now wondering if it could be something I am doing wrong or contamination, but the paint goes on well with no marks.

Could this be a unique problem with the colour Saffron, as I have sprayed a few cars over the years and never encountered this problem before.

I have tried spraying different metal test cards with and without primer and a couple of different high gloss premium thinners and thin coats, but still having the same problem.

It could be that the paint just needs longer to fully dry and cure. I read somewhere that nitro paints can need up to 90 days to cure.

Any thoughts and advice appreciated.

[poppyman]

Has the paint been "polished" ?  If so, what type of finishing polish did you use?  I had this a while ago with "celly" paint and had the same reaction.

Tony.

[Mark B]

HI Tony

The marks first appeared on the un-polished panels and I used T-cut to remove them.  This is a test card pictured, easier to photograph than the actual panels. After lightly polishing away the marks off everything, and waiting a couple more days I again sprayed it with water along with the rest of the panels leaving it In the sun to dry resulting in the new etching where the droplets sat. This is the same for all the  panels painted so far. I have repeated polishing the marks away, exposing to water and sun several times since after initially painting them four to six weeks ago, and each time I have been left with the etch marks.

I did try some Mur polish on one half of the rear valence after t-cuting all the water marks off, thinking it may have created a barrier, but it made no difference when I sprayed the panel with water the whole valence was effected the same.

If I leave them out of direct sunlight to dry I still get the white marks on the paint but not so much etching.

I have ordered some G3 finish polish which I was going to try.

To be honest I am at the end of my tether, and running out of ideas.

Mark

[Pete Lewis]

http://thepaintwebsite.com/paint-defects-causes-and-solutions/technical-basics-relating-to-paint/helpful-guide-about-paint-problems/

 

My first car was a resprayed 53 Minx in bright red, she would water mark when it rained , and the paint was a few years old, polish was the only solution to hold it back and that was the old one step hard wax , hard work stuff.

Reds were often poor for this , look at some old vauxhalls, 

Not many clues in the link other than keep it dry,   not very helpfull

Pete

[Colin Lindsay]

Happened on my red GT6 Mk3 all the time, mostly on the bonnet, which I took to be the heat from the engine drying the water out quickly leaving the residue, whereas it naturally ran off the rest of the car over time. Hot sun can do it too, on the roof or other exposed areas. As Pete says it had to be polished off regularly, just ordinary polish and no t-cut or other abrasives.

[poppyman]

Hi Mark,  Pete is right, you need an old style hard wax. I sent an email to mer about this problem and they were great explaining modern wax's contain a chemical called "Naptha" that reacts on certain paints. They told me to strip old the old wax's off the paint using white

spirit or similar, but to test on an small area first to make sure it does not remove the paint   They then told me to buy G3 professional supergloss paste wax, which i did. It did take ages to do but the results were fantastic... And then i had no more problems   It seems this "naptha" attacks paints at random as i have used mer for many years with no problem. I dont think colour matters as my car was light blue.  I hope this might solve your problem. I dont think the G3 finish will solve the problem? But you could try emailing Farecla and ask if it has "naptha" in it. Keep us all posted  

Tony.

 

[Mark B]

Hi all

Thanks for all the replies and advice so far, much appreciated.

The problem is that I didn't apply any polish to the fresh painted surface and the water marks appeared in the fresh untouched paint.

I only used T-cut to remove the etch marks once they appeared.

I then tried Mur to see if it would prevent the water marks but had no effect.

I'll try the G3 Finish when it arrives and see if it prevents the etching.

I am starting to wonder if it could be the water droplets magnifying the sun rays that is etching the surface, which makes me think the paint is still not cured?

Help!

Mark

[Clive]

G3 is a fine cutting compound? I use it after a respray on a mop to get the finish to shine nicely. 

Afraid I haven't used Celly paint for years, but yes it takes months to really go hard, especially if it has fresh celly primer/undercoat under it. 

[Pete Lewis]

when the cars wet wash off with a watering can with rinse aid added , dont use much , just a good squirt

all the water runs off and leaves it  droplet free,  

well its good when washing the car , !!!

Pete

[poppyman]

3 hours ago, Mark B said:

 

I am starting to wonder if it could be the water droplets magnifying the sun rays that is etching the surface, which makes me think the paint is still not cured?

Help!

Mark

It is the sun's ray's Mark. Mine was ok if wet in the garage.

Tony. 

[Mark B]

Hi all

Had a helpful reply from the first paint purchased manufacturer, which is possibly relevant to all nitro cellulose / acrylic paints.

 

The edge of evaporated water droplets can be seen on the paint surface.

CAUSES When water drops on the paint surface and evaporates (especially on horizontal surfaces) the outline of the drops may still be seen.

This happens when the painted surface has been exposed to rain or water drops just after painting.

REMEDY Allow the finish to dry through, then:-Sand and polish.-If repeated polishing is not effective, sand the affected area and re-spray.

PREVENTION-Protect the car immediately after the painting and avoid contact with water before it has dried through.

 

I think all your replies have covered this, and I may have not allowed long enough between coats, put the primer on to heavy, exposed the paint to water before the paint has completely cured which I now think could run into months.

A rep had mentioned to me a while back to try and sand the surface and leave it to help the remaining solvent to evaporate completely.

I can still Mark the paint surface with my finger so definitely not cured.

Today I stripped the boot lid back to bare metal and I am going to start again, leaving longer intervals between each of the primer coats and finish coats and then leave alone out of the elements for s few weeks before sanding and polishing.

I think I know where I've been going wrong, thanks for all te advice.

Mark