Otter LRC CM4647296 comes home

[Jordan Baker]

Removed the ends of the fuel tank. At first I tried melting the solder out and uncrimping the edge. It wasn’t working too well and was making a mess of the edge. I ended up using the flap disk in the grinder and simply took the top of the fold off. This went very quick and I was able to remove the end panels. They will get formed back into shape. As suspected the internal baffles were popped from a few tank walls. I will remove them as well. This will give me the access I need to get the rest of the tank cleaned up. This will also let me work on getting the side walls of the tank back into shape. I also removed the senders and the pickup tubes.

[Jordan Baker]

Lastly I found some kind of screened filter loose inside the one tank. Not sure if it’s original but more research is required.

[David Dunlop]

Not exactly a ‘Holy Grail’ but quite a surprise inside the tank.

It looks far too course to be a fuel filter in the conventional sense, but it looks like it might slip into the throat of the filler pipes to catch larger objects. If filling these tanks was an awkward task in a confined space, the filler caps might have had chains fitted to prevent their loss into an inaccessible place. One would also not want to lose one of those chains into a fuel tank, so those screens might have been used to prevent important stuff from falling into the tanks for all eternity.

Another long shot.

Back in the 70’s, I worked up in Yukon doing geology, using helicopters in remote areas. We had a string of 45 gallon drum fuel cashes strung up the Richardson Mountains to give the pilots the range and endurance they needed to move us about. Part of the kit they carried for refuelling was a chamois and a large hand fuel pump for the drums. They would wet the chamois and give it a good ring out and line their fuel funnel with it before pumping the fuel in. For some reason, the chamois let the fuel through but stopped any water from getting into the helicopter fuel tanks. It also stopped sediment passing through.

Maybe that screen served a similar purpose when used with a petrol can and flex hose fitting...?


David

[Jordan Baker]

The end plates and baffles were removed and straightened up.

[Jordan Baker]

The tank looks quite decent inside. There is one spot to patch up, but otherwise it’s quite solid. It will be a bit of work getting the creases out and everything back into shape.

I’m contemplating buying a kids wading pool to make up a dipping tank to chemically clean up the tank. I figured one side can soak at a time and it can just be rotated.

[Jordan Baker]

Not much to report. But I’m trying out a citric acid bath on the fuel tank. I had a large plastic drum that I filled with about 40 gallons of water. Into this I mixed in 10lbs of citric acid. I bought a bag from Amazon. I had been reading about home versions of Evaporust and the citric acid was deemed to be overall pretty mild.

I was able to submerge about half the tank at a time. This is the result after soaking since Sunday night. At first it didn’t look like any changes were taking place. But after power washing, wow it cleaned almost all the rust right up. Tonight I added a much larger fish tank heater (rated for 90 gallon) tank. The dip is supposed to work better when it’s warmer.

[Jordan Baker]

Pretty happy with how this tank cleaned up in the citric acid bath over the past week. Power washing it out really gets it cleaned up and flushes out the gunk. Next up will be stripping the remaining paint off. Then soldering up the pin holes.

[Jordan Baker]

For the past 4 days or so I’ve had the drivers seat base soaking in the citric acid bath. After power washing the seat off I was quite happy with how well it cleaned up. I know in the picture it still appears quite rough, but other than some variation in metal colour, the rust was gone. I decided to give it a once over I the blasting cabinet and it came out very clean in a minimal of time. I also cleaned up the early style seat runners.

[Mike Kelly]

That's a neat method for heating up the citric acid/water solution , a fish tank heater

Just wondering how the ends of the tanks can be re-used after the top edge of the folds have been ground off ?

[Jordan Baker]

The 90 gallon fish tank heater works great in the 40 gallon bath.

I’m planning on welding the fuel tank ends back in.

[Jordan Baker]

Seat mounting parts and drivers seat base all painted up.

[Jordan Baker]

Turret basket seat getting some rebuilding love. The original seat pan and back rest frame had taken some heavy rusting due to the open top of the turret. Initially I was going to weld up all the rust holes in the tray. However after looking it over again I decided to replace the seat tray. This involved cutting off part of the frame mounts and then using the original angle iron brackets from the Otter seat. The Otter also had a third lift the dot stud along the front of the seat. One had to be removed from the back of the seat and I soldered it in place at the front. The seat pan also needed 8 holes drilled in for the turret basket and Bren magazine parts to bolt in place.

[Jordan Baker]

The turret gunners foot rest getting the full rebuild. It was in really great shape and just required a strip down, some minor welding and a repaint. The part was held in place by 4 rounded head slot screws that had seen better days. Access to the nuts was blocked by a frame cross member. I ended up using a Zip disk to cut off the heads of the screws. The downside to this was cutting a bit into the steel base just below the screw heads. So once the part was cleaned up I welded up the cut marks and ground them back down to make the mounting blocks flat again. As for cleaning up the part, it was given a quick needle scaler pass and then dropped into the citric acid bath. After 4 days I pulled it out and power washed it off. Pretty much all the left over paint came off and I had some pretty nice clean metal. It was given a spray of Zep degreaser, hosed off then finally sprayed with POR Metal Prep. Finally for painting I brushed on the POR15 and once slightly tacky it was over sprayed with the white paint.

[David Dunlop]

Were you loosing your marbles in that first photo, Jordan?


David

[Jordan Baker]

Originally Posted by David Dunlop

Were you loosing your marbles in that first photo, Jordan?


David

Haha. They were the turret ball bearings that dropped everywhere when I was removing the turret ring.

[Jordan Baker]

Really enjoying this citric acid bath for rust removal and now also a caustic bath for paint removal. These parts had some serious heavy rusting to clean off. It would have taken a few hours of work in the blasting cabinet. Instead I left the parts soaking over night and they came out pretty clean. A few spots still had the heavy post war Dutch paint. However the needle scaler made short work. The caustic bath was made up using Purple Zep cleaner. With the heater in that tub the paint is simply melting off the seats. Tomorrow morning I should be able to hose off the remaining paint and then leave them in the citric bath for 24hrs. The stuff will then be ready for painting. The finished up parts comprised of the two antenna mounts, shovel handle bracket, pick axe handle bracket and combination bracket that held the shovel blade, pry bar end and pick axe handle.