Clear Over Base ON TOP of Celly?

[SpitfireIV]

It ma be an adhesion issue, difficult to be certain without seeing it in person. Some looks like the gun spitting and other areas look like grinning. If you refinish it, it would be interesting to know what you find as you go down.

I might hit it again with a bit of 2000 and see if the darker areas grow larger, I think this would give a clear indication of it being and adhesion issue. I've only cut back and polished half this panel. I'll examine the other half carefully for any visible issues before I cut and polish it.

In other news I think I'm finally happy with the bonnet, it's had another final flat back and spot priming. There was a stress crack in the gel coat that had appeared on the front of the bonnet, passenger side. I tried filling it and hoped it'd go away, but it wouldn't do decided to just bite the bullet, root it out and add a fibreglass patch before filling and priming...

Guessing it's not gonna be on the road this summer....

 

[SpitfireIV]

So I hit the panel with another bit of 2000 and polished it. The two darker patches, as such....

Became a larger patch meaning I was indeed cutting through the top layer that hadn't adhered or merged with the previously applied coating....

For an amateur who will be spraying in an unheated 'booth' what's the sweet spot to look for before applying the next coat. Strings that pull away from the panel when touched with a finger? Or a tackiness like touching masking tape?

 

[steveo3002]

wet finger = wait longer

leaves a finger print = ready

 

[bert]

Depends on the paint and hardener you are using but 5 to 7 mins between coats is normal.

Some paints never blend between coats, mipa OC nd PPG doesn't especially on pastel colours and you get that haloing effect if you sand through a coat

 

[SpitfireIV]

Depends on the paint and hardener you are using but 5 to 7 mins between coats is normal.

Some paints never blend between coats, mipa OC nd PPG doesn't especially on pastel colours and you get that haloing effect if you sand through a coat

In my naivety I didn't know which brand of paint I had, I went back to the supplier and got the details.

So it's Max Meyer UHS Duralit Extra.

The TDS states finish existing paint work or primer with P360-400 or Scotchbrite extra fine.

And then regarding coats:

"Single Visit Process: Apply one medium, continuous, coat followed by one full coat. The
first coat should be applied to all repair panels before the second coat is applied. For less
than 3 panels, 2-3 minutes flash between coats. For more than 3 panels, no flash is
required.
Two coat Process: Apply 2 full coats with a 5 minute flash off between coats."

I'd be nervous about just two coats, surely that doesnt leave a lot of meat on the bone for wet sanding/cutting/polishing or for any future cut and polishes?

 

[qwakers]

you've flatted that back through the lacquer

 

[SpitfireIV]

you've flatted that back through the lacquer

Yeah I left the recoat time far too long. While there was still a bit of a tack to the paint on touching it obviously wasn't enough. You live and learn

 

[qwakers]

not so unless you left it 24hrs or more.

a generic except from a random solvent basecoat tds.

Base coat First Coat	Application URKIMIX PRO SB 5000 according to TDS
Nr. of layers Thickness	Succesive coats for a correct matching
Thinner evaporation time	5-10' between layers or until matt
Drying time 20°C (70°F)	20-30' before applying the clearcoat Recoatability max. 24 hours

 

[richie00boy]

Ultra high solids paint is designed for professional/expert use and it probably wasn't really appropriate for the vendor to sell you that. It's designed so that an expert sprayer can lay on one or two thick coats without running it everywhere, as a time saver.
A medium solids product is better for DIYers as they can be laid on in thinner and numerous coats. I don't believe you can thin UHS to achieve the same effect.
By all means try again though with what you have, just try and follow the intended process a bit more closely.

 

[bert]

So you won't ever be able to lay that paint and be able to sand through a layer and not see haloing.

I had to paint a concourse mini in grey with Mipa OC and then flat and polish without going through the first layer. That wad the last time I used mipa oc and now only use mipa AC as the binders in it are designed to allow better blending of the layers.

Some colours especially pastels like the one you are painting will always halo.

 

[Slowcoach]

Do you know what the little dots are I’ve marked? It may be dirt in the paint but it looks like they’re there after flatting and polishing.

 

[bert]

I can't really tell from that pic, could be dirt between the layers, bits of paint not mixed up properly or solvent pop

 

[Slowcoach]

I can't really tell from that pic, could be dirt between the layers, bits of paint not mixed up properly or solvent pop

You have to enlarge it but at first look it seemed like silicone but not easy to make out, don’t know if it’s primer showing through

 

[bert]

OK managed to make it bigger, they look like silicone or something on the primer before you painted.

 

[ajlelectronics]

Solvent pop perhaps. Silicone contamination would give fisheyes, inclusions would be obvious by their irregular shape.

 

[bert]

Solvent pop doesn't normally show all the way down to the primer after 3 coats of paint. It's normally very small pin holes but not through the whole layer of paint.

 

[ajlelectronics]

Solvent pop doesn't normally show all the way down to the primer after 3 coats of paint. It's normally very small pin holes but not through the whole layer of paint.

Yes, agreed. It is so difficult to see it in the photo.

 

[SpitfireIV]

Do you know what the little dots are I’ve marked? It may be dirt in the paint but it looks like they’re there after flatting and polishing.

View attachment 461909

They're little spits of rain or possibly dust, therw was nothing on the surface that alarmed me apart from the cut through. I'm primerily a woodworker so anything I leave down in the shop tends to get dusty very quick. I use a turbine sprayer so their shouldn't be any contaminants from the gun

I have little experience with UHS 2K direct gloss so this is indeed a learning curve but plenty of experience spraying 2k polyurethane for the day job using the turbine...

 

[SpitfireIV]

Today was a good day.....

Finaly got some colour on!

The weather here in Ireland is fantastic this week, the summer we never had. So this was the week if ever there was one to get some paint on. So with one measly day scraped aside I set to work firstly on my state of the art, ultra modern spray booth....

I'm sure youre no doubth all envious of such a modern marvel . This is the car storage but today would be taking on the role of spray booth after a good clean out, hose down, mask up and then a vacuuming!

Then I got to spraying! (Plenty of pics coming.....)

The plan was to get the boot lid and bonnet sprayed today and then out into the sun to bake and harden.

First up was the boot lid.....

(^ lot of dust on this after it had been outside for a few hours)

The result was really good. A nice gloss, very very soft orange peel but overall really pleased. I'll not kid you, given the location in the countryside, the vegetation all around there was some bits of debris in the finish but nothing that can't be flatted out.

Then, onto the bonnet!

This, like the boot lid received two good coats and then out into the sun to bake! Very pleased with the results, nice deep shine and gloss, like the boot lid some minor debris got in. Again, soft orange peel on the wings but the upper areas etc came out nice and smooth.

The pics below were taken a few hours after the spray so dust etc has landed on it....

To be continued....

 

[SpitfireIV]

(^ again, lot of dust after been in the sun for a few hours)

Now, I'll not lie, all did not go swimmingly! On the very front lip of the bonnet and one of the wheel arches is a couple of nice runs/sags, I may have gotten overly generous with the application of paint!

They were hard to focus on because of the sun/reflection but I think the above pics capture them.

Can these be easily rectified? Leave the paint cure for a week or more and flatten them back after nipping the bulk off with a razor blade? Will there be a difference in tone from the non saggy areas?

Right, well all in all delighted with the days work, been a long time coming and big thanks to everyone that offered me help to get to this point. At least with the bonnet done it's one big section, the rest of the car can be broken into smaller sessions, the weather however may not be on my side with that time comes....