Mottling (Flotation / Flooding) - in solid colour 2k (non-metallic)

[tomaxcars]

Hi Chaps,

I'm having an issue with mottling as described here: http://pc.dupont.com/dpc/en/US/html/visitor/s/trouble/PDSG_Mottling.html

Oddly it's in a solid colour where in most instances it's described as occurring to the flakes in metallic. As you can see from the pics attached the lighter pigment seems to be "floating out".

The paint is 2k Monopol, in a grey. The paint is thoroughly mixed, at the correct ratio by volume of 2:1:10%. Using a fast reducer.

I'm spraying on the flat with a gravity fed gun (1.4mm) as I find the orange peel to be less, less possibility of drips, any small dust inclusions I can 1200 grit out, and I have a lot of large panels to spray (classic range rover) so they're tough to hang.

Having read as much as I can it seems likely that it's down to uneven spray pattern - which I think I spotted towards the end of painting yesterday where more paint was being sprayed towards the bottom of the fan than the top. I'm onto my third coat so it's grey on grey at this stage. I'm going to filter the paint and remove the internal filter also in case it's getting blocked and causing the issue.

Any other suggestions gratefully received fellas. Pics attached.

Cheers,

Andrew.

 

[eil]

What is the condition of your air cap and nozzle, hold your gun a hand span away from a piece of paper on the wall and with the horns of the aircap upright pull the trigger so you have a horizontal spray pattern wait till the paint starts to run then trigger off. you should have a even paint run. if you don't turn the horns 180 and try again, more paint one side and it moves to the other side when turned would indicate a doggy aircap..

 

[norsa]

Whilst the above is correct and consistent with your spray pattern, from the pictures i would say the fault lies in the substrate, not the paint or spray pattern.

 

[the snooper]

im with norsa the pattern in that paint is nothing to do with the gun, what thinner are you using, not the universal type by any chance ?

looks like something to do with old repairs or recent flatting that has maybe gone through the laquer where the pattern is

 

[Chipper]

Could eliminate the gun via similar but different paint, on a test panel. But does look like something's leeched into it. What's under it, and what primer? Was it completely covered or were there patches from sanding layers etc.

 

[steveo3002]

id be thinking stale paint , incompatible hardner /thinner , or something in the airline

never seen it happen like that , only a big of colour drag on a big run

 

[langy]

I'm with Nick, it looks like something underneath

 

[tomaxcars]

Thanks for the input fellas.

1. I checked the spray pattern as advised and using this as a guide: http://www.vivilon.com/pdf_articles/GTi pray Pattern Poster May04.pdf - it all seems to be ok - no bias towards one side or the other with the horns spun through 90 degrees.

2. The panels are all coated in a couple of coats of upol 4:1 high build primer. blocked between coats. I made sure to re-coat anywhere that had gone through to lower layers before final paint. Stopper was used for pin-holes and small scratches but this had all set up fully before over-painting.

3. The thinners used is the monopol thinners supplied with the paint + hardener. So it isn't gun cleaner or anything not for the purpose. I've used the same monopol paint before but with upol hardener and sikkens reducer without this problem occuring, but it was a different colour and mix of paint.

4. Also the sunroof panel (right hand side) of the attachments as pictured has already had 2 coats of colour, and there wasn't any filling done on the panel, yet the problem still appears. So I'm fairly certain it isn't coming from beneath.

5. I'm fairly sure its not coming from the airline as I have a good number of filters inline.

6. I tried spraying a panel on the vertical (the same sunroof panel), to see if it was some sort of gravity thing happening on the flat, but the same separation seems to occur.

7. My last effort is A) change the thinners out for some sikkens fast reducer B) Also then try the Upol hardener with A.

8. If that doesn't work I can only assume that it's a paint problem as steveo3002 has suggested. Maybe an incorrect tinter in the lighter colour with a different density or something so it's separating out? The paint was only mixed up last week. As I say, I've used the same paint in other colours before without issue.

Again thanks very much for the input.

I'll keep you posted.

Andrew.

 

[the snooper]

Thanks for the input fellas.
3. The thinners used is the monopol thinners supplied with the paint
Andrew.

monopol is the brand not type of thinner, ive had similar problems with the universal type thinner causing a reaction on certain areas of a panel.

i doubt very much it will be a paint issue or it would be a uniform thing right accross the panel

 

[norsa]

Its a mystery for sure and now you have answered the questions and eliminated the possibilities from the pro's, you have 100% grounds for recompense from the supplier if he supplied paint hardener and compatible thinner. Clearly a bad batch of tinter/ mixer error.
Nick

 

[norsa]

Just a thought, you did use a decent panel wipe and cleaned off pre flash off and tack?

 

[pedrobedro]

Is your paint shop heated and dry ? The weather lately has been bad for home painters.

 

[tomaxcars]

Again thanks very much for the input folks:

1. Yes indeed monopol is the brand, but it's the specific thinners I was provided as part of the system "L900" for the paint. Pic attached.

2. However, I did a test last night using Upol hardener and Sikkens thinners and the same result.

3. All panels were panel wiped, and tacked.

4. The spray area is as good as it can be in terms of dryness etc. - i've been spraying other solid colours (blacks & greens) without any bloom or similar so I don't think it's this.

5. So with all avenues tested I think it has to be a problem with the paint. Attached is a picture of separation of the paint in the gun hopper that I spotted after only 5 mins of spraying. It was thoroughly mixed in advance. The same separation appears to be happening on the panel anywhere the paint is a little thicker and thus taking longer to set.

6. I was just wondering does anyone know if a water-based tinter or similar could be the issue? The inclusion of the hardener and thinner is what causes the separation. I tested this separately in a glass jar.

I'm going back to the supplier today and hopefully it'll be resolved. I'll keep you posted.

Thanks again,

Andrew.

 

[tomaxcars]

Separation pic attached also:

 

[norsa]

That doesn't half look like basecoat mix in the cup. We wait with baited breath.
Nick

 

[the snooper]

That doesn't half look like basecoat mix in the cup. We wait with baited breath.
Nick

ie you mean base mixed with straight 2k ?

ive done this in the past for a non vehicle paint job (couldnt be bothered to go to get any paint) and it did separate like in the pot but not once sprayed.
will the supplier admit fault ?

 

[norsa]

Kind of. I'm pretty sure the supplier cocked a label up somewhere and we have incompatibility.

 

[norsa]

Basecoat tinter in a 2k binder??

 

[langy]

I've not heard of Monopol paint, always worries me when I've not heard of a paint