Trent's RV14 Build: Engine Overhaul: Testing paint colors / Painting begins & An Expensive Parcel

Choosing the Paint / Colours

Many hours (and cans of paint) were spent choosing what type of paint was best for the engine, and a good looking color palette. It would be labourious to go thorugh all that, but i tried the Duplicolor range of paints and didn't think they were very tough. I moved onto the VHT line of engine enamels and testing showed that these would be durable, so long as they were cured as per the can instructions. The test pieces were bashed with a spanner, and showed no signs of chipping. (fingers crossed anyway).

In the end i have chosen the following color scheme:

In the beginning..

..there was prep! Before any good paint job can begin, the surfaces need to be cleaned. Since many of the aluminium parts had been sent away for NDT (Dye Penetrant Inspection), they were covered in the white developer power, which needed to be cleaned off. This was done with the high-pressure degreaser. We also had not alodined the sump (we initially thought it might have been magnesium), so that was also done.

Next up was all the masking! The overhaul manual has the following statement regarding painting the engine:

The engine shop had mentioned that they paint under the nuts on the case (with the exception of the cylinder hold down nuts). I was not sure this was correct, as i everyone i had seen online seemed to mask off the hardware locations. I reverted to the forums and it seems that the general concensus is that, while the case hardware is not included in the "special torque" table, it falls under the "standard torque" table - so all hardware locations should be masked.

It took a whole 55m roll of tape to do the job on the below parts:

These dots worked out great - 15mm is the perfect size.

These were 14mm paper - didn't peel off very easily. Don't use these!

Rear prop-governor cover plate

Oil Pressure Regulating Valve body

I used blu-tac in the blind holes - this worked ok, but you have to be very careful to remove all of it from the threads.

Vacuum pad accessory drive

Magneto extension - i don't think i'll need this, but i painted it anyway.

Oil Filter mounting / vernatherm assembly. The pink dots were replaced before painting.

For the accessory case machined bosses, i used the gaskets as a template to make a mask.

The magneto extension was used for the shape needed to mask the magneto bosses.

I masked off all of the studs, but left the tops open so they get some paint.

This is foil shown in the sump drain plug holes - in the end i found some PVC pipes which screwed in and worked a lot better. They also allowed me the leverage to rotate the sump when painting.

These are the intake tube flanges at the cylinder end. I masked off where the flange interfaced with the mounting boss.

Pushrod tubes

Finally Painting

The painting process was fairly repetitive, but for each part i used the following procedure:

Clean everything one last time with ISO, and make sure all the tapes were down.
Shoot VHT Primer in a light-ish coat - wait 10 mins.
Shoot VHT Primer in a medium coat - wait 30 mins.

The Titanium Silver Blue parts (pushrod tubes, seal retainer rings and intake tubes) all got the following:

Light coat of color - wait 10 mins
Medium coat of color - wait 30 mins.

The Anodised Blue parts (accessory parts, sump), all got the following:

Medium coat of Natural Aluminium - wait 30 mins
Light coat of Anodised blue - wait 10 mins
Medium coat of Anodised Blue - wait 30 mins.

The once the respective color coat was done, clear coat was shot in a light coat - 10 mins, then a medium coat.

I waited a few hours, then removed all of the masking while the paint was still soft.

Here are some glory shots!

Pushrod tubes / Seal Retainer Rings

I made up a quick jig to hold the intake tubes.

I recommend this paint - it sprays very nicely.

Seal retainers were held using a sliced paper towel tube.

This shows the Titanium Silver Blue next to a test pushrod tube which was painted in Natural Aluminium. The cylinder heads are going to be painted Natural Aluminium, so these should look good together.

Masking at the engine case end...

... and at the cylinder end.

The little seal retainer rings will sit here.

Intake Tubes

The intake tubes are just mild steel, so these got buffed with a scotchbrite then degreased multiple times before painting. These ones have the mounting boss permanently on the tubes which made painting a little harder - i sprayed some paint around the flanges, then waited 10 mins. Then lowered the mounting boss into position and painted the whole thing. These were also mounted on a little jig for drying - to actually paint these weird shapes, i masked off the ends which went into the sump, so i had somewhere to hold them! I will check with the shop, but i think i'll just leave these bare where they insert into the sump (airbox plenum).

I masked off the ends which go into the sump - i could have probably painted these, but needed somewhere to hold anyway.

The cylinder ends got some primer before waiting 10 mins, then lowering the mounting boss into position to prime the whole tube.

These would have been impossible to paint without being able to move them into weird positions by hand.

Color on the cylinder ends, before lowering the mounting bosses into position.

This color makes me happy!

Accessory Case and it's parts / Oil Dipstick Tube / Oil Pressure Regulator housing

Primer

This is the Superior Aluninium Dipstick Tube. This was anodised gold, so i just scuffed it with 320 grit and cleaned it off before painting. Hopefully it sticks!

This was a tricky part to paint!

Natural Aluminium

Anodised Blue

This should look pretty good once the CAD plated hardware is installed.

All the accessories in place

This shows the Titanium Silver Blue intake tube against the Anodised Blue case. These look pretty nice together i think.

Sump

The sump took a little planning, but i was able to work out a procedure to rotate the sump and get all sides painted in one session.

Primer

Natural Aluminium Undercoat

Anodised Blue Topcoat + Clear

Rocker Covers

The rocker covers got the same treatment:

I do enjoy baking...

Finally, everything was baked at 200F for an hour in the oven. The sump did not fit, so will need to be done at the big oven at the airport.

An Expensive Parcel / Engine News!

In other news, I heard back from Joel at Suncoast, who is overhauling the crankshaft, counterweights, conrods, case and cylinders. The crank has thankfully polished up well at M03, so i am able to go ahead and order the bearings. By the time this post is made, the parts have arrived back at the shop. Once we have the bearings, we can check the dimensions on the case etc, then i can paint the main cases themselves.

Sitting on the shelf at Suncoast, waiting to come home.

The parts which came back took awesome - the cylinders look brand new. The conrods were all good and the corrosion burnushed our with no issues.

I also recieved the most expensive parcel i've ever been sent - and the courier just left it on my doorstep! Gulp.

All parts accounted for - and the camshaft has begun it's journey to New Zealand to be drilled out for the tappet oiling modification (Suncoast modified the cases to give an oil journal to match the camshaft).