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.

Replacing The Outer Sills - Follow Up

I finally finished replacing the sealing strip around the front door. These strips crimp the outer black rubber door seal to the door frame.

Rusty sealing strip....... 

Water creeps up inside these unseen. Don't let anyone tell you they have a rust-free DS if they haven't replaced these!

It was the UK Citroen car Club's 'D rally last weekend and I took the opportunity to order one of the front door sealing strips from Citroen Classics. They are a very awkward shape to post but Citroen Classics usually have a stall of parts for sale at the rally and will bring along parts ordered and paid for in advance. It was too good a chance to miss.

The crimping strips have a 'W' profile to grip the rubber seals outside the doors and the trim inside the cabin. 

The crimping strip is '1' in this drawing

Removing the old section.......

Cutting through the spot welds

...........revealed quite a horror story!

Not what I wanted to see!

Though it turned out it was only really the thin metal crimping strip - the bit I was replacing - that had rotted away. Crumbling pieces of old old dried seam sealant made it look worse than it was and the ridge of the chassis, that the channel fixes-to, was actually in quite good shape once it was cleaned up. 

Even though the strip I'd brought was shaped for the curve of the front door frame, some significant fettling was still needed to get them to fit the curve.

The patch doesn't quite follow the curve

Because the metal needs to be soft enough to be crimped, it's quite thin. Many DIY car hobbyists rely on MIG plug welding. The problem with thin strips are that they are difficult to plug weld with a MIG without burning through. There are modern automotive adhesives that could be used instead but, with the patch needing help to follow the curve of the door frame I wasn't convinced an adhesive would hold it and decided I would spot weld it - just as I had done with the other sections. 

Paint stripped off and ready to weld

I started welding at the top and forced the strip onto the seam as I went along. It was never going to follow the curve 100%, but I was pleased with the result. I plug welded the bottom part where it sits on the outer sill and it was every bit as tricky as I'de been told - especially for a welding novice like me. However i got there in the end and, with this past piece done, I'm one step nearer to painting the front half of the car!

Replacing The Outer Sills

I'm building up to painting the engine bay so that I can put the engine back in plus replace many, many other parts removed along the way.  

Patiently waiting for paint

In the first instance I was planning to paint as far back as, and including, the 'A' posts. I would include the scuttle but not the roof, and I would paint the 'A' posts but not the sills/ door openings. Including the 'A' posts meant including the area where the rubber door seal fits. That had been removed when I removed the outer sills back in May 2020. You can read about that HERE. The upshot of all this was that I needed to finish that sill replacement job before I could do the painting I planned.

I'd cut the new pieces to size.......

I'd replaced the mounts that hold the spring bar. You can read about that HERE.

I re-used the mounts off the parts I removed

And had primed and painted the parts.

Inner faces primed and painted

With the underside and sills of the car stripped and painted (you can read about that HERE) it was finally time to finish the job!

I'd bought a spot welder for some of the repair work and decided to planned to use it for this job - rather than plug welding.  I started by cleaning the surface of the sills on the car.

Preparation before welding

There are pros and cons with spot welding. Once you are set up, the welding is quicker and there is no plug weld head to grind down. However there is more prep......For the electrical conductivity needed to spot welding two flat pieces together, both sides of the two pieces need to be clean, shiny and free from rust and paint. In my case that meant cleaning all the underseal and paint from the underneath edge of the sill lip. All four surfaces got a spray of weld-through primer and finally I was ready.

The parts were carefully lined up to the two vertical ends......

All lined up. Spot welder at the ready

.........and then spot-welded along the top.

Spot welds along the top edge

The spot welds were quick to do and looked neat. Unfortunately, of the four panels I'd bought, the pair of front panels already had holes in them for plug welding. So as well as spot welding them, I also had to plug-weld and grind the holes.

Spot weld and plug weld holes!

The next job was to weld up the vertical and bottom edges. I started with a few tacks and then filled the gaps in.

I took the opportunity to replace the rubber holders in the bottom of the 'C' posts and on the 'B' posts. The 'wings' on these rust and the rubbers fall off. Getting the old ones off is not easy. I found one of the 'C' post ends was quite rusty  - because the bottom of the post was silted up with mud and muck. 

Muck from inside the 'C' post 

What was left wasn't strong enough to weld a new seal holder to. You can buy replacement sections for the bottoms of the posts but I didn't have one and didn't really need to replace it all. I just cut out the bad bits. At least it meant i could drill through the other welds from the inside - leaving the outside intact.

Repairing the 'C' Post

It was all tidied up (I made sure the seal holder fitted inside).......

.........The seal holder was fitted.........

..........And I used the spot welder again.

To cut out the old sills, I needed to butcher the lower section of the channel that hold the door seal rubbers around the door frame.

Door seal holder on a 'B' post

These channels have a 'W' profile with the two arms of the 'W' crimping onto the black rubber outer door seal, and the interior door frame trim.

The crimping strip is part '1' in this drawing.

I'd bought a couple of straight sections when I bought the new sills and now put them to work. 

Door seal channels - ready to go

I was able to spot weld these where they fit over the seam on the posts, but plug welded them to the new sill sections as access was limited. This wasn't easy. the strips are thin steel and very difficult to weld without burning through.

Welding in a door seal channel

There is a section of strip around the leading edge of of one of the front doors that looks very suspect. I wanted to replace that too, but it is on a curve and my straight sections can't be used there. 

Rusty crimping strip on a front door

You can buy replacements that include this area - but it's part of a strip that goes most of the way around a door aperture - waking it expensive and awkward (and costly) to post. It will have to wait for the moment. Another delay to painting the engine bay. Will I ever start!?

Cleaning The Engine Bay (Part One)

Over the past few months I'd been rotating between jobs to try to keep myself motivated. While my zinc parts were being plated I cracked on with work to clean the engine bay.

March 2022

By now, the whole engine bay area was starting to look far healthier than it had when I first 'rediscovered' the car in the barn.....

Engine bay - April 2015

Back then, I'd given it a wipe down with white spirits and a pressure wash. 

Engine bay - September 2015

Having got that far, the chassis pretty much stayed that way for another five or six years while I gradually removed and worked on the pieces that were bolted to it.

Engine bay - January 2020

All the engine bay pipework had been removed back in January 2020 and to give me better access to remove the suspension units.

Engine Bay Pipework

And about a year later I removed the suspension units. you can read about that HERE. With the pipework and then the suspension units out of the way, the years and years of road dirt and grease were visible.

Muck.....

.....muck.....

......and even more muck.

It all took some shifting. And meant even more removal of parts to give me the access I needed.I started with the front suspension areas as, being under the wheel arches, those areas seemed to have picked up the most muck.

As good a place to start as any....

There is a cluster of hydraulic pipes that run front to back along the left hand sill. On later cars there are in two parts with a join near the middle of each - beneath the 'B' pillars. But on my car each pipe is a continuous length. 

Hydraulic pipes under the left hand sill

Each end is shaped and so they can't be removed without bending and weakening them. Or cutting. I did wonder whether I could cut each pipe to remove it, then add a new flare and nut to the cut ends. All I would need to buy was the join pieces for the middles. I reasoned that the size of the join piece might compensate for the cut. However my pipes were in good condition and the joints were a balance between convenience and added cost (plus loss of originality) - so I decided to work around them.

Pipes emerging from the left hand sill

I didn't want to use Jizer and then need to rinse with water for fear of it flooding into all the seems and gaps, so I used white spirit in a spray gun (or stippled on with a brush) to loosen the dirt, and then rags and tissues to clean up the black runny mess I created. Gradually the dirt started to loosen and revealed shiny paint beneath. Well that was a surprise!

I removed the remaining pipe clips and fittings and gave everything a whizz over with a wire wheel on a drill to remove loose rust and paint. 

There was a surprising amount to do but it was very rewarding to start to find solid car underneath all that muck.

The first of many piles of dirt

After cleaning the two wheel arch areas I moved on to cleaning the 'tusks'. These are awkward shapes and it was slow work. At least I had already cleaned and painted their undersides.

Not much rust but an awkward shape.

All of this cleaning work took several passes to move dirt, loose paint, stubborn paint and surface rust. I started using a wire wheel brush on an electric drill - but that really didn't have much impact. 

Starting to see the difference

I ended up using a wire cup on an angle grinder and a twisted wire wheel on a different angle grinder - alternating between them as the task dictated.

Gradually I got back to bare metal - with no nasty surprises along the way.

Some nice details starting to emerge

Back to bare metal

I ended this phase by degreasing everything with panel wipe. Twice! And then giving everything a wash of phosphoric acid to kill any remains rust. This time I was happy for it to find it's way into seams. I'm leaving the cleaning there for the moment. I need a change again to keep me motivated.

All covered with phosphoric acid