Spac’s Adventures in Mercedes

Spac · 2020-09-16T06:11:19+00:00

Paid $200 for this including delivery. It is an M271.980, same as what’s in my car. 200,000km old, blown head gasket. I grabbed it because I figured it would...

Spac

Busy day with other things, not much done on the Merc.

Actually, this is pretty much all of it: adding the braces to the spread beam driving lights.

The original plan had been to fit a second rivnut on the back of the light bar, but then I realised that using a common one was a better load path … and less work.

jamesinc

What temperature is the metal when you paint it? It might just be too cold

Spac

jamesinc
What temperature is the metal when you paint it? It might just be too cold

The problem was first noticed when the weather was still good.

It is like the old problem of painting acrylic over enamel, but happens with paint from the exact same can.

Leaving it for weeks between coats doesn’t avoid the problem either.

Philia_Bear

Sand

Acid dip

Wash

Wipe with isopropel

Paint

Bake in second hand $50 scumtree oven for 2 hours

jamesinc

Maybe it's reacting with a contaminant left behind by the welding? Pretty weird though, unless it's just garbage paint ?‍♂️

Spac

jamesinc
Maybe it's reacting with a contaminant left behind by the welding? Pretty weird though, unless it's just garbage paint ?‍♂️

First lot was Rustoleum Appliance White. It hardens off really well for an aerosol paint and has a slight yellow tinge that is a fairly close match to the original paint.

Then I tried the inferior White Knight quick dry stuff because it doesn’t ever seem to react with anything … but it reacts with the Rustoleum paint.

Spac

My nose hairs all turned white today.

Still a bit more to do - I missed a few parts and couldn’t get to them until the rest of the paint dries… Mostly the rear legs.

Because I can’t buy the decent paint in town (the local hardware store is hopeless), so I bought the cheaper stuff … eight cans of it. If I had known at the start, I would have bought a tin of paint and cracked out the spray gun…

Also put seam sealer on the inside and outside of the fuel pump box. I am comfortable that this is not actually needed, but it stops anyone arguing about whether it is sealed or not.

Super conscious about the risk of this being misinterpreted as hiding shit welds, so took lots of photos of it before.

After the paint went down, I sealed up a bunch of the gaps around the place. This is mostly to make it easier to clean and avoid washers and electrical terminals finding hidey-holes, but should also help stop dust working it’s way into the car.

Still more to do, but it also tidies up the interior a surprising amount because now it is all white. There’s parts around the roll cage that I want to do, but will hold off until after the logbook inspection.

Will finish the painting and sealing (that I can do) tomorrow, and then hopefully will have the self control to stay out of the interior for a few days so the paint can harden up.

rado

It's always a bugger deciding weather to buy an obscene amount of rattle cans or get the spray gun out hey . Good work though. Nice work on the sealing as well

Philia_Bear

20L tin of gloss white house paint and the cheap ozito sprayer every time

Spac

Looks the same!

…but I actually spent most of the day working on it.

Painted the rear legs, did a bunch of work on the nav’s seat mount, and heaps more sealing.

The sealing up is a frustrating process because I “have” to leave alone anything important that has been welded. So I have needed to consciously stop myself from sealing up things like the gap at the bottom of this plate - it is all welded solidly to the sill, it is just this part where I didn’t run the weld back to the horizontal.

Here’s where the seat mount finished. It is more elaborate than it needs to be, and I am seriously considering remaking them…

Oversized washers to take countersunk bolts.Under floor counterplate. Spacers (more on that later). The big captive nut from an earlier post. Fat washer, just because.

The floor (with 5mm plated welded on, see below) goes between 2 & 3.

Here’s what it looks like from underneath. Bevelled arrow head on the front is to reduce the chances of it catching on the scenery. It is about five times larger than the minimum mandated area, but I chose to do it this way because it is stiffer, stronger and only has one leading edge.

Spacer from the top. Could just be floating, but it wasn’t much more work to attach it to the mount, which makes installing the seat a LOT easier.

Cut-out section is to clear the foot plate for the rollcage mount where it overlaps the seat plate.

Still bolts into the captive nut.

It all goes together super well - the bolts slide straight into place and the seat doesn’t rock when it is just sitting on the floor (without any bolts).

However …

I have a problem with adjuster of the inner lap part of the harness *just* hitting the hole on the seat before the load is taken by the harness mount. It is so close that it will just flex the seat in a crash, but it is not right and I am not going to just ignore it.

Genuinely perplexed how this can be a problem - it was just a problem when I had the seat mounted lower, and now it is about 30mm higher and I still have the exact same problem to the same degree?!

So… I need to remake the harness mounting plate with the mounting hole lower. It will be a bit tricky to maintain the correct angle between the mounting point and the nav’s pelvis, but should be possible.

At that point, I would like to lower the seat back down, and probably make new seat mounts like the driver’s side.

Or maybe I should just get on with it and stop fussing over the minor details - this mount is vastly better than most…

Spac

Light switch mounting plate.

Boring but important and tedious to make stay for the dash

Making fuse box panel Mk2.

Cheesy, fake action photo

but it works out ok.

Still need to work out the correct angle for the upper mount and the length to trim the panel down, but that will have to wait until the paint is a bit harder.

jamesinc

What sheet are you using for the panels? 1.2mm mild steel? I can't tell if it's steel with a coating or aluminium

Spac

jamesinc
What sheet are you using for the panels? 1.2mm mild steel? I can't tell if it's steel with a coating or aluminium

It is 1.2mm aluminium, and yes, it is a funny colour.

I would have preferred 2mm but I have the 1.2mm in stock. With the edges bent, it is stiff enough.

Spac

So the fuse panel is a lot shorter (top to bottom) that I expected. Previous measurements were before the handbrake went in, and were working on the theory that it would be more rearward in the car, and would angle rearward toward the bottom, both of which would make it a bunch longer.

I had to take 15mm off the top, and cut the bottom a lot shorter than originally planned.

Bottom mount is a short length of 40x40x3 aluminium angle bolted to the top of the transmission tunnel.

There’s also a business card size piece of 2mm aluminium on the front (hidden) side to spread the load. When I made this from 1.2mm, it was based around the idea of having four mounts. Because it is now so short, the single lower mount has to be between the fuse boxes.

It is going to be fine with the three mounts - the stiffening plate spreads any load into the footprint of each fuse box. This, combined with the folded edges and stiff top mount make the whole thing plenty stiff enough.

Also pleased that both the fuse board and the lower dash can be removed independently of each other. This was the original plan, but it was all getting a bit dicey with everything being changed at the last minute …

Spac

Spoke to the Autronic Guru last night about a variety of things, including the mounting of the SMC and the CDI unit.

This morning…

Next was the oil catch can. The aluminium cube was made by a workmate as TIG practice. I grabbed it from him, planning on painting it white and making it into a novelty oversized dice, but then realised that it was just over the 3-litre capacity mandated by CAMS and was far more valuable for that purpose.

I could/should have gotten the fittings welded on, but stubbornness won out.

Then a bunch of over-complicated brackets, that also should just be welded on…

Ample urethane goo in/around the mounting holes means that it shouldn’t leak. Second photo below shows why it is angled off the firewall. Additional benefit is that the drain is now the lowest point.

And here’s the tap for the drain. I would put a one way valve in and let it auto-drain, but I think that it is too low relative to the engine for that to work well.

I think that it will end up with a hose down somewhere near the sump plug, so both can be done into one drain pan.

Still need a proper sized vent, but that will need a suitable filter that I don’t have yet.

On to the battery tray.

Looks pretty straightforward, but of course there was a bunch of time and effort in getting it right. If I had identified the need to step up to match the contour of the shelf before I started, then I could have made it in one piece as I originally planned.

The two very short studs are the original battery tray mounting points. The bolt pointing downward is shared with the CDI box.

Tomorrow’s first task is to work out how to make the hold down strap. I have a couple of ideas, but what actually works best will take some more thought.

Spac

Battery hold down strap worked out well.

The doubled up aluminium flat bar was trickier to work with than I expected. If you bend both at once, it gives you a big radius bend, so I had to bend the inner piece first, and then bend the second one over it.

I drilled and tapped a couple of holes to make life easier.

Failed to take a photo of the bracket. It is a short section of 30x30x2 RHS that I cut into a U-section. There’s an 8mm bolt with a length of 10mm OD tube as a crush tube.

It is held to the firewall with a couple of short 8mm bolts and a load spreading plate. The nuts are welded to the bracket.

Worked out nicely.

Also fitted the aftermarket washer bottle, which was a time consuming job … because I lost the bracket and spent ago looking for it … twice.

Made the bracket for the isolator switch, and also fitted the toggle switch for the RallySafe. This is actually a bit naughty because the RallySafe is supposed to be hardwired on, directly to the battery. The trouble is that there’s an LED in the cable, so it flattens the battery between events. Having a switch that is out of the way should avoid flattened the battery while not being likely to be bumped off during an event.

Spent a fair bit of time working out how things will go through the firewalls. And then more time working out how to make the washers for the gland nuts to reduce the varying size of the holes in the firewall. Some of them were easy because the firewall holes were large and I could cut out a large piece of aluminium and then hold it in the vice to drill the inside hole. I had a few washers that were the correct size… but the rest sucked.

It was impossible to hold the washers and open up the inside hole to 22mm when the OD was relatively close in size.

Eventually worked out that I could clamp them between two plates and drill them that way. Still a slow, tedious process.

And then only took a photo of one that just used the normal washers…

Ex850R

Ally works best with some heat.

Idealy you heat it and rub a bit of wood on it such as a wire welding brush handle , if it leaves a mark its ready , too much and its all blobby on the ground.

Spac

Ex850R
Ally works best with some heat.
Idealy you heat it and rub a bit of wood on it such as a wire welding brush handle , if it leaves a mark its ready , too much and its all blobby on the ground.

The blokes at work cover it with soot from an acetylene flame, and then turn the oxygen on too, to burn the soot off.

But I don’t have an oxy/acetylene kit here.

carnut1100

Spac
https://ozvolvo.org/discussion/comment/206782#Comment_206782
The blokes at work cover it with soot from an acetylene flame, and then turn the oxygen on too, to burn the soot off.
But I don’t have an oxy/acetylene kit here.

Another way that works is rub a bar of soap on it like a crayon and heat from the other side until it turns clear and disappears.

Ex850R

Bit of timber is better for the lungs than other methods,esp acetylene smoke and if you use natural or LP gas you don't have that option.

Boilermakers are filthy cunts and don't use soap Greg......

Had to heat full size sheets of 12mm ally to bend on the brake press back at Alcoa, some of it funky grade that cracked if you looked at it sideways and it would actually break off at 90° without heat, another lesson learned during 2nd year of apprenticeship. Good times.

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