More painting tests

I'm still looking for the perfect mix.
If you don't want orange peel add Penetrol and Turps to your paint... But to much Penetrol and/or thinner will cause the paint to shift; The uniform paint colour will get patchy.

Shifted paint in tray

My custom made colour shifted in blue with some green spots in it, especially when the coat was a bit thicker. If you look at the panel you won't see it, but as I'm a perfectionist I noticed it when I was checking the paint with a 500 watt floodlight.

Only visible when you take a real close look

OK, so what's the perfect balance between the ingredients. To much additives will cause shifted paint, No additives will cause massive orange peel. Hmmm..., time for some more tests.

Do your maths
On Internet you can find mixing ratios of paint with Penetrol and thinner.
For example: add 25% Penetrol and 25% Turps. But... is the % based on the volume of paint you start with or on the volume after adding Penetrol and turps ? This can make a huge difference.
Example: If you take 400 ml paint as your starting point; 25% of 400 ml is 100 ml --> 100 ml Penetrol and 100 ml Thinner. So you'll end up with 600 ml mix.
However if you take 600 ml mix as the starting point the mix gonna be 300 ml paint, 150 ml Penetrol and 150 ml Thinner.
Instead of % I think it's better to talk about parts or ml;  2:1:1 or something like that.

Back to the mix
I replaced the Turps with the recommended thinner for Toplac; Thinner No1. Hopefully that will make a difference..

Trying different things...

Tonight I made the following mix: 3 parts paint - 0.8 parts Penetrol - 0.5 parts No1 Thinner (Ok,ok,ok, if you really want percentages :.. 69.8%-18.6%-11.6%).
Tomorrow will tell...

Replacing the B20B Valve seats

Last week the outlet valve seats were replaced by new hardened ones. If you want to use lead free petrol or LPG you need harder valve seats than the original  valve seats who are directly cut into the edge of the valve port of the cast-iron Volvo B20B cylinder head.

And while the engine was still disassembled I brought the cylinder head to Chris Milton Engines
Sam took some pictures of the whole process.

Cylinder head Volvo B20B

Cylinder head and new exhaust valve seat

Removing the old valve seat

New uncut valve seat in place

Cutting valve seat 

Cutting valve seat

Valve seat cutted

Refined shape of outlet port with new hard valve seat

Ready

Sam also did a vacuum test on the inlet valves; all good. Normally there´s no need to replace the inlet valves because they get less hot then the outlet valves.

Painting experiment

Time for some painting!
Because I'm still waiting for engine parts I decided to kill time with some experimental painting on the Volvo body.
The Volvo122S  really needs a paint job. The original paint has faded, is cracked and on the hood and roof it's even flaking. On some spots you can see the bare metal and there's a lot of surface rust.
Because I didn't know what should be the best way to get rid of the old paint I tried several things. I used the right front panel as my test panel.

Original paint on the hood, a lot of surface rust...

• A wire brush on the drill - to slow 
• A grit 80 sanding disc with the angle grinder - to aggressive but you can use it for areas with surface rust
• Chemical with paint stripper - is OK but not as fast as I taught it would be
• Finally I got the fender back to bare metal with a combination of paint stripper and the wire brush drill

Almost bare metal Volvo 122S fender

Next step was to prime the fender. I tried rolling on Dupont 2K high solids primer (1040R). This primer is suitable as an enamel undercoat/primer (who cares??... well.. read on ;) ) It's very smooth to roll but you'll  get more orange peel than with spraying. So I sanded it back and applied a second and third coat with a simple 1.8 mm spray gun, much better. When I'm gonna prime the whole car I'll use a Dupont surfacer under the primer but for now this will do.
The next day I sanded the primer with 240, 360 (dry) and 400 (wet) grit.

After 3 coats of Dupont 1040R primer, before sanding

Now it was time for some painting. I got some quotes for spray painting... 8000-10.000 dollar for a real good job, (including engine bay, boot and interior) and still 4000-5000 for a quick job. Hmmm... what are the other possibilities...

I started searching the Internet and read a lot about painting your car with.... a roller...
Well, as I was still experimenting with the fender I bought some paint at Bunnings. I chose White Knight Epoxy enamel because that was the only paint that could be custom colour mixed. The mixed colour wasn't an exact match with the original blue (Volvo 99) colour but good enough for the experiment. I mixed the paint with 25% Penetrol and 20% turps. It rolled on pretty smooth but there was way to much orange peel. I also discovered that this paint wasn't UV stable. Time for a different brand.

International  Toplac.
This is original oil based yacht paint, high gloss, durable and UV-resistant. The only problem was that this paint only comes in ca 12 colours. As I wanted an exact match with the original Mediterranean blue colour I bought 3 different colours of Interlux Toplac and started mixing them (Oxford blue, Squall blue en Donegal green). I used a glass jar and 5 25 ml syringes and wrote down how much I used from each colour.I worked in 1 ml steps at a time. After an hour or so I found the exact match fort the 100% paint mix. But.. what's the ORIGINAL colour...The Volvo came with the radio cover wrapped in a newspaper from December 5 1970, so that's the real non faded colour.
Then I added 25% Penetrol and 25% Mineral turps. The colour changed a little bit,  but still very very close to the original 99 colour.

Radio cover Volvo 122S 1969 - Original paint and colour

Ingredients and tools for the Toplac paint mix

Roll it on.
To apply the paint I used a 10 cm foam roller with a round top. To keep the paint tray clean just put in a new piece of aluminium foil after each coat. The trick is to keep the coats as thin as possible, so squeeze out the roller before it hits the body.  It was obvious that the Toplac is a much better paint which flows better, has more gloss and less orange peel.
According to several stories on Internet it takes between 6 and 10 coats to get a good result. And sanding between each or second coat is also necessary. I sanded the previous coat with 400 (because it had a lot of orange peel from the White knight paint) and then 800(wet) . Now waiting for the results, will the colour be the same when it's dry...

First coat of Toplac mix (underground was already blue from the previousWhite Knight experiment)
 now waiting for the results...

Update 15-7:

It's looking good both the colour match and the quality, almost no orange peel. I just sanded it back with 800 wet and applied the next coat.