Painting The Engine Bay

 Well, I finally got there! I finally got round to painting my engine bay!

I can hardly believe it!

For years, this had been a key milestone for me as it would mark the turning point between dismantling the car, and reassembly. Many was time I had thought back to when I'd first 'rediscovered' my car in the farm barn back in September 2014. This is what had faced me.

My rose-tinted plan then had been to get the car to start, hose the engine bay down with a pressure washer and then merrily drive off into the distance.  The reality was that there was a lot of grease, grime, rat shit and surface rust. And so the engine came out....All of this saga forms the earlier posts in this blog.

But now everything, including the scuttle area, had been stripped and de-rusted and was just begging for fresh paint.

All prep-ed

However a little more patience was needed......

I had been using a compressor and air tools as part of the welding on my car. I had recently chosen a compressor with the best CFM value I could afford with spray painting in mind. But now I was finding out all about 'dirty' air from the 'mig-welding.co.uk" site, and how it can run a paint finish. I won't go into all the details but part of the problem is dust sucked into through the compressor, part is water which condenses as air is compressed and, as I have an oil lubricated compressor, part of the problem is oil particles in the air. 

'Micro-blistering' used by moisture in spray air
(photo by mig-welding.co.uk)

It would particularly be a problem for the finish on panels. Perhaps less so for a chassis, but what not aim for the best finish i (personally) could get? Taking a lead from the MIG welding site, I set up a filtering system between my compressor and my planned spray gun. The principles are explained HERE.

In my case I bought a relatively inexpensive triple stage filter regulator, plus a range of fittings from a plumbing supplier to join it to copper piping. The filter was capable of producing 'breathable air'. Handy if I wanted to spray with 2 pack and needed to 'suit up'.

Particulate filter and fittings

My garage was going to double as a spray booth. I rigged up a run of copper pipe from one side of my garage to the other - including a couple of drop legs for removing moisture along the way.....

Mobile compressor with a 'whip hose' link to the wall

Note the gradual slope in the pipe

......all terminating in the particulate filter at the end. It was close to my workshop door meaning i could alternatively spray in there if I wanted to.

A dedicated air outlet for my spray gun

I used solder and flux joints. partly because I had a load and partly because there was no risk of them loosening up. In hindsight the flux potentially introduces grease and particulates into my air line, but most of the jointing is before the filter and there is only one 90 degree elbow after.

In terms of paint, I didn't want a high, 'wet look' gloss finish as I felt it would look out of keeping with the age of the car. I certainly didn't want a matt finish. In fact I didn't want a satin finish either! I wanted something that was more than satin.....but less than gloss! After much dithering on my part, I bought Eastwood 'Extreme Chassis Black' as it was thin and sprayable. To get the kind of finish i felt I wanted, I planned to try mixing 67% satin finish with 33% gloss finish. As recommended by Eastwood, I used their 'Extreme Chassis' primer for consistency.

You'll be aware that we had several heatwaves this summer. One of the benefits of this is that it was great weather for painting - with low humidity, lovely dry air and quick paint drying. For a while I'd been scavenging and saving polythene sheet and crudely lined my garage walls and floors with it, using duct tape to hold it up wherever I could. I went back the garage the next day and it had all fallen down in the heat! That was one of the downsides of the heatwave. It was soon put back up but I had to keep adding more end more tape over the next week or so.

Home made spray booth

I realised that if my compressor was left in my spray booth, it would pull in paint-filled air and soon clog the filter. I'd kind of anticipated this and had left my compressor mobile and so simply set it up in my workshop instead - which was also where I do all my paint mixing.

The engine bay was rubbed down using a Scothbrite pad, vacuumed several times and then wiped over with panel wipe. Everything was masked - and then vacuumed again. I applied a primer coat. I was really pleased with what i was able to achieve as a complete novice. 

Primer coat

And when it had dried seam sealed in strategic places before applying a stonechip coating to the 'A' panels near the foot well and to the 'tusks'.

Seam sealer and more masking

My first gloss coat was a mix of 67% satin finish paint and 33% gloss. I was pleased with the finish but still thought it was too glossy.

First gloss coat

Happy with the finish but......

.....too glossy for my liking

There was a lot of rubbing down between coats to key the surface. Plus vacuuming, plus panel wipe. But that also provided thinking time and, for my second gloss coat, I decided to mix 85% satin with just 15% gloss. It was all guesswork.

This time I was far happier with the finish. It is still glossy, but definitely not nearly as shiny. And definitely more gloss than satin.

Second gloss coat

But I'm a novice - and it's not perfect. It's a complex shape to paint and in places I wasn't consistent with the distance of the spray gun. There are also a couple of places where I didn't pull the trigger fully and I was essentially just spraying air over wet paint. This has the effect of roughening the surface of the paint previously sprayed. But none of these faults are serious and none in the areas that really matter.

In parallel to this I've been rebuilding my suspension arms and am looking forward to refitting them, but there are a few pipes and hoses that need to go on first.