Intercooler Build
Turbo Mini Forums

Right, not wanting to be considered idle, I've started to build up my intercooler for the 998 Turbo.

For starters, a nice Pace custom built core:


A plan of sorts:


Some 2mm aluminium sheet marked out. (It is scribed accurately, I just need to add the felt tip so that I can see to cut it):


One end tank plates cut:


Next job is to cut out the other end tank plates and then try to weld it together.

I've never welded aluminium before, so this may end in tears. Wish me luck.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Schrödinger's cat - so which one am I ???

Try leaving an overlap on yuor parts, so you can melt this to form teh joint, instead of always adding filler.


ALthough Im crap at welding alloy too lol But thnat should offer less chance of blowing holes

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

With TIG welding ally you need to be brave with the current- too low and it will just "wick" all the heat away leaving you with a frustrating blobby mess.

for somthing like a cooler, 10 min in the oven may not go amiss.

gas mark 3 ? what do they taste like?

I run a supercharger and I don't care the TB is on the wrong side.
VEMS + 12 PSI + Liquid Intercooler = Small Bore FUN!

Yes, high amps and nerves of steel are needed by the sound of it.

Most of the Youtube videos of alloy tig welding show the welder working at one hell of a speed. Comes with practise I suppose.

Anyone tried "pulse" welding? Looks like a good way of preventing too much heat build up.

Edited by Paul S on 2nd Jun, 2009.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Not enough heat is more your problem Paul TBH. If I were you I'd seriously consider cutting some more bits to practise on before going for it for real. In actual fact depending on how much the core cost I'd probably tack it up and then get my mate Phil to finish it off!!

Tom, lots of practise on scrap is planned first then only when I'm ready will I start on the end tanks.

The core cost about £100 so I wont risk it if I'm not happy with progress.

I've got the phone number of JF's mate who does the plenums in case I bottle out. He's only in the next town.

Edited by Paul S on 2nd Jun, 2009.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

IS that the general idea then ? blast it with high current, and move fast ?


Ive managed a few oik welds on thicker materials, But generally focussing the weld to a small area like steel seems impossible, and blowing holes is very easy.

Id be fairly slow at it though.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

This is inspiring:



Note that he is using a peak current of 180 amps on 2mm thick aluminium!

Edited by Paul S on 2nd Jun, 2009.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

To do that takes real skill and a very steady hand...

I've watched the coded welders at work do similar (but not on alloy) and I could never do the same....

I've never used over 80 amps on thin alloy...

Schrödinger's cat - so which one am I ???

Well, I was itching to have a go, so instead of watching springwatch, I went and fired up the Tig:



Dial in some settings I thought would be a good starting point, including pulse.

Started second bead up on the right and thought this is easy but then things got progressively worse after fiddling with a few settings.

I think that as the plate got hotter with the additional welds, it got trickier.

Tried the edge joint, but blew a hole half way, filled that and then got a huge hole at the end.

Finally tried the foot pedal to reduce the amps, but I think that the pedal is working backwards i.e. foot down to reduce amps.

Have another go tomorrow.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

http://www.youtube.com/watch?v=rR8Rlpf0ELQ...re=channel_page

Easy nothing to it, lol.

Over the last two years I have been fortunate enough for my firm to pay for a couple of evening courses at college on tig, I finished the mild and stainless modules in good time and started the ally module in advance of next year. I sat for weeks trying to find what works best for me and found the pulse setting a god send, you could use it to blast the workpiece without huge heat build up allowing a pornounced weld profile, the other thing I found good was it was easy to get a good rhythm with the filler wire listening to the pulse and adding filler wire just after it pulsed (if that makes sense) also found it easier using a larger diameter filler wire as this deposited more material thus slowing down the rate you have to work. This is only what I found, and doesnt necessarily mean is right? lol
Cheers
Shane

On 2nd Jun, 2009 Paul S said:
Well, I was itching to have a go, so instead of watching springwatch, I went and fired up the Tig:



Dial in some settings I thought would be a good starting point, including pulse.

Started second bead up on the right and thought this is easy but then things got progressively worse after fiddling with a few settings.

I think that as the plate got hotter with the additional welds, it got trickier.

Tried the edge joint, but blew a hole half way, filled that and then got a huge hole at the end.

Finally tried the foot pedal to reduce the amps, but I think that the pedal is working backwards i.e. foot down to reduce amps.

Have another go tomorrow.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Shane, pulse mode does seem to work best, although my cheap chinese tig has limited setup and the fixed pulse rate is a bit fast for my liking.

I use high frequency, 70 Hz to get good penetration and a short slope down to stop it from creating a crater at the end. The current level seems to be difficult, too high and you have to work quick, too low and you end up going too slow and everthing gets too hot.

Robert, thanks, I hope it only gets better.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Larger dia rod certainly seems to make things easier I have found too. Something else I tend to do is a small dip of rod right at the end, again to try and avoid a crater.

Thats a shame as I believe you would really benefit being able to adjust pulse rate. It will be a trial and error affair, what is right for one person mite not be great for you, a friends fiancee's farther can sit with thin filler wire feeding it in at a great speed, weld away and sit looking you in the face while he chats, but I guess its just experience.
Shane

the main issue with welding ali, is all down to preperation of the metal. makes sure its very clean, use acetone if you can get some or give it a good rubbing with some scotch bright.

make sure you are using the right code rods as per the material, find tthe code for you ali, i pressume the sheet you have is just 52510 ? do a goole search and use rods with correct silicon content,

if its 14g at work i would normally use 65amps and when you start really wait for the weld pool to form at the begining even if it take somes time to get it going, if your stuggling to get the beat good try a 2.4mm rod. although rule of thumb would be 1.6mm.

are you using a 1.6mm tungsten, possibly with a number 4 ceramic, to really provide a decent shroud. make sure when you sharpen the tungsten to do it to a dome, not to a point.

once you have donee this, get some scrap, turn the amps up to 150 or so, and really burn into the scrap, this should give you a very shiney nicely domed tip. now your really to go

the rest is down to pedal modulation, i don't bother with the pulser at work, more effert than its worth. its all down to practice.

good luck

That's very useful, Thanks.

Well, not sure about the plate.It's just a sheet of brushed aluminium from Ebay.

The filler rods ar 5356 and 2.4mm diameter.

I'm using a 2.4mm thiorated(?) tungsten with a white tip. The cup is a number 4, I think.

I had sharpened the tip, but found that it had domed after a short while, so I sharpened it again :$

I was using something like 120 over 75 amps on the pulse. It started well but I had to move faster than I could feed the filler with my left hand, so the bead got wider as I went along.

Do you use the pedal to control the amps throughout, reducing as you go or do you continually modulate to create each weld pool?

I'll have another go later.

Edited by Paul S on 4th Jun, 2009.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Sharp tip for DC, soft tip for AC. I had all this to find out too!

White tip tungsten is zirconiated - which is correct for alloy (thoriated (red tip) is for steels).

As said, ball end on the tungsten for AC.

Just to show everyone is different, I can't stand foot pedals but my welder has dual current settings so I use that to the same effect. Welding the runners, thinnest bits 3mm, thickest bits 12mm I used a 2.4mm tungsten and filler wire but was only using 80A to start and down to 65 once the bits got hot. I also had the AC duty cycle set well over to cleaning rather than penetration.

Schrödinger's cat - so which one am I ???

After a few more trial runs, I found settings that I could work with. Around 80 amps with pulse and use the pedal to start it off quick.

So went in for real and welded up one tank:


That's the only good weld all the way along. All the others had blemishes so I linished them to tidy them up.

Then it all went badly wrong when I decided to weld in the end pipe. Somedays the die grinder is your best fiend.


Do the other tank tomorrow, but I think I'll get a professional to fit them to the cooler core.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

looks good, something id like to learn...

Yes i moved to the darkside

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