Aluminum TIG welding for cooling and aircon

Designing and creating the cooling system expansion tanks was only half of the story. Next step was putting it all together. Since I do not have an AC TIG welding machine nor any aluminum welding experience, Mischa from Garage 71 did this for me.

Alu laswerk Mischa

I had prepared and marked all components so it was ‘just’ a matter of putting everything together.

Grote expansietank lassen

Altogether quite some work, pieces of art almost!

Alu laswerk ronde 1

Custom airconditioning compressor suction port adapter

One of the parts was a modified adapter for the suction port of the airconditioning compressor. That’s where I had a challenge to solve.

Knelpunt airco compressor aansluiting

The adapter itself would fit behind the fan but there was no room for any connector, line or hose.

Geen ruimte voor airco slang en connector

Moving the fan was not an option since that would require moving and thus redesigning the radiator. So I puzzled on a new adapter.

Alternatieve airco adapter

Would also be quite complex to have that CNC’d. In the end I decided to buy a universal aluminium airconditioning weld bung with 7/8-14 UNF thread to be able to modify the original adapter.

Originele adapter plus universele las adapter

And after some measuring, cutting and filing I had an angled adapter.

Haakse adapter airco suction port

Which was also welded by Mischa.

Adapter airco gelast

Finish of the expansion tanks

Back home I wondered, how will I finish the expansion tanks? Keep the welds visible ‘as is’ of grind them off.

Las bovenste deksel grote swirl pot

Las bovenste deksel kleine swirl pot

I decided to create a smooth top and grind the weld.

Grote swirlpot afgewerkt

Kleine swirlpot afgewerkt

That does trigger a new question however. How to protect the aluminum from corrosion?

Because of the welding and sanding the protective layer is partially gone. Having them anodised is too expensive. I am leaning towards painting them since it will degrade otherwise. So the question is: What paint color? Can’t choose between satin black or just matte black. I am going to use the same color for all the mounts and supports that I made. Satin or matte, your vote is welcome in the comments.

Installing the expansion tanks in the car

The small expansion tank is for the DC/DC converter and the controller and will be mounted on top of the controller. I bought some closed aluminum rivet nuts. By choosing closed ones, the DMOC645 controller remains completely sealed and cannot be damaged by using too long bolts by accident.

Dichte alu blindklinkmoeren

So I removed the cover and after double checking whether there was enough room for the rivet nuts inside I drilled the holes.

DMOC cover eraf en gaten boren

After installing the rivet nuts the swirl pot could be mounted.

Controller expansievat geplaatst

The large expansion tank for the batteries is supported by the battery box mount but needed a little extra mounting tab at the top.

Steuntje voor batterijen swirl pot

It needs to be welded in a second round.

New temperature sensor adapter

Another item for the second round was the adapter for the temperature sensor. I made this from some aluminum tube and as a result it had become very light and thin and could not be welded into the distribution block.

Te lichte adapter temp sensor

So I made e new one from a solid piece of aluminum hexagon I had laying around. With a seat so it nicely snaps into the distribution block.

Much more body.

Nieuwe adapter temp sensor

And ready to be welded as well.

Nieuwe adapter temp sensor gereed

Another nice job by Mischa!

Gelast batterijen koel verdeelblok in

Blockvalve & evaporator

Another puzzle was the thermostatic expansion valve of the cabin evaporator. Initially I planned to use the thermostatic expansion valve with integrated solenoid from a Tesla. However it turned out to be quite complicated to mechanically connect that to the evaporator I am using. So I have decided to use a separate valve and use the thermostatic expansion valve that matches the evaporator. So this needs to be fit together:

Airco verdamper aansluiting puzzel

The connection is exactly opposite from what I need so I tried bending the tubes 180 degrees.

Poging buisjes buigen

Without much success…. But I had another idea, just drill all the way through the adapter.

Door adapter boren

That worked out quite nice!

Passend blokventiel

Until I realised I also have a blower and was exactly in the way.

Blower in de weg

Luckily I could slightly tilt the tubes and make it fit exactly.

Blokventiel schuin

And also that adapter has been welded by Mischa!

Blokventielaansluiting lassen Mischa

So now the heater/airconditioning unit is almost ready.

Blokventiel op kachel Amazon

TIG welding aluminum myself

Finally I could give it a try myself on some waste material. Not too bad for a first aluminum TIG weld I’d say.

Zelf alu lassen

Wish I had bought an AC/DC TIG machine instead of just DC.

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OldVolvo is a classic Volvo hobby blog by Lars Rengersen.

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