Welding Tips and Tricks

I am a retired hobby welder (old construction crane operator / heavy duty mechanic) with a Diversion 180 I converted to a WP 20 flex/water cooled torch. I have had it for a few months after using a scratch start setup on a buzz box for the last 10 years. I do pretty well on plate aluminum such as building the tank for my home brew water pump.

My son has a small centrifugal water pump on a sprayer he forgot to drain last winter. The housing is cast aluminum and probably 12" - 14" in diameter. There is a freeze crack on the OD of the housing that is not really open but it leaks.

I plan to V grind the crack before attempting to weld it. I have never welded cast aluminum and would appreciate any tips to do it right. What filler rod would be best? I have on hand EP 4043 1/16" - 3/32" / ER 5358 - 1/16 - ER309L 1/16" - .045 and ER316L-1/16". The welding supply store is close by if something else would be better. Thanks for any help provided. This forum is something I read nearly every day.

Jim
Bellingham,WA

Hi I've been TIG welding cast Aluminium parts for over 25 years so it's not at all a problem, you first need to clean the part really well, if you have a die grinder with a tungsten burr that is ideal, if not a grinder with a new disc if not a file then a stainless steel wire brush, then some Acetone or if you don't have that alcohol. Preheat the part with a gas torch if you see impurities coming out use the stainless steel wire brush. The 4043 filler is perfect for cast Aluminium the other most commonly used rod in Aluminium is 5356 and this I would recommend if it was exposed to seawater. Pure Argon gas, 15cfh, No. 7 gas lens if you have one, and make sure there is no wind blowing away your gas. If you use a 2.4mm(3/32) Tungsten sharpened electrode and a 1.6mm (1/16) Filler rod this will allow you to get a nice fine weld into the route of the crack, you can then do a cap with a 2.4mm(3/32) filler. You did not say what the wall thickness was but remember to pre heat with a gas torch so that it is hot. Welding Aluminium always think about heat dissipation. That is when you weld the heat is quickly sucked away by the rest of the material, so if you heat the rest of the material your weld will go along much better.

Jim -

I agree with all that Moto has to say regarding cleaning, just thought I might add that while 5356 will probably be fine, I've also had good results using 5183 filler - seems to wet in a little easier and flow nicely.

All the best with your repair.


Kym

Thanks guys. I have most everything mentioned to get it done. I have a Dremel and small rotary files I plan to use to V the crack out. KYM-I will check with my local welding supply store and see if they have a 1 pound tube of the rod you mentioned. Can't have too many options.

Off the 16th for a week in the motorhome then I will tackle it. No idea how thick it is but I doubt if it is very thick. I have a heat temperature gun - how hot should the pre-heat be? I have Acetone for cleaning after SS brushing it.

Thanks again for the help. I will let you how it goes.

Jim

jim
wipe down with acetone before you wire brush then again
after if you want.
craig

Something I forgot to mention. I have a Tig Perfect Pulser I have not yet gotten familiar with how to set it up properly. The instructions are evidently written for someone that has a very good understanding of the techinical terms used for pulse setup. That is not me. I don't understand the terminology they use. I am going to have to e-mail him and see if I can get a laymans translation of his terms used. I would think its use might be benificial for a project like this.

If anyone here has one and could translate the terminology for me I would sure appreciate it! I figured out how to set the pulse time but I am lost in how to set the high output verses the low side of the pulse. If for example I am welding .125 aluminum I would suppose 125A (One A per thousands of a inch) for the welder setting (yes-NO ?) What do I set the pulser high number and the low number? He uses the term Background as one of the settings plus some other terms (I'm not home) and I don't know what they means ???

Jim

jauguston wrote:Something I forgot to mention. I have a Tig Perfect Pulser I have not yet gotten familiar with how to set it up properly. The instructions are evidently written for someone that has a very good understanding of the techinical terms used for pulse setup. That is not me. I don't understand the terminology they use. I am going to have to e-mail him and see if I can get a laymans translation of his terms used. I would think its use might be benificial for a project like this.

If anyone here has one and could translate the terminology for me I would sure appreciate it! I figured out how to set the pulse time but I am lost in how to set the high output verses the low side of the pulse. If for example I am welding .125 aluminum I would suppose 125A (One A per thousands of a inch) for the welder setting (yes-NO ?) What do I set the pulser high number and the low number? He uses the term Background as one of the settings plus some other terms (I'm not home) and I don't know what they means ???

Jim

High should be full amperage, background would be described as low in your own term. Frequency/HZ would be the number of pulses per second, and on time is typically a percentage of how long the arc is on the high side for a percentage of a complete cycle from high to low.

Sent from my SM-G900V using Tapatalk

Thanks Grein Time. That will help a lot. When we get home from our RV outing I will experiment some more wih it.

Jim

Hi typically for pulse welding you have the high amps or welding amps at a higher ampage than normal welding
current 30 to 50% higher and the backround or low amps at 30% of the high current. I hope that helps.
Cheers Bert

Moto,

Yes- that helps a LOT! Thanks !!

We are going to have to cut our RV outing short and go home today as our Yorkie is not feeling well and will go to the Vets when we get home. I will try what I have learned here then. Thanks all of you for the help. I love this place !!

Jim

Id also recommend lightly peening the alum as well

Rick,

Can you explain a little more what you mean by peening. I am going to V the crack before welding. The crack is not open its just a freeze crack in a round pump housing maybe 12" in diameter that leaks bad when running. Its shaped like a bowl or half of a basketball. I'm not home now so I am just guessing on the diameter and won't know the thickness until I V out the crack. I would not be surprised if it is not much more than 1/8" or slightly thicker cast aluminum. Also what trmperature should I pre-heat too.

Jim

Kym,

I have located some 1/16" 5183 rod. Hard stuff to find especially in one pound lots but Welding Supply.Com had some and sold me a pound for $15.00 plus shipping. Not bad! I have 5356 also 1/16". What am I going to find different between the two? I may try the pulser also.


Jim

jauguston wrote:Kym,

I have located some 1/16" 5183 rod. Hard stuff to find especially in one pound lots but Welding Supply.Com had some and sold me a pound for $15.00 plus shipping. Not bad! I have 5356 also 1/16". What am I going to find different between the two? I may try the pulser also.


Jim

Hey Jim.

My own experience in directly comparing the two (yours may vary...) is that the 5183 seemed to melt at a slightly lower temperature and wet into the weld area more readily. It's not a night-and-day difference, but it's definitely there.

When I was welding a cast aluminium 1970's Volvo radiator grille for a friend I found that the 5183 behaved well and just made the whole job that little bit easier.


Kym

Peening is stress relieving so you would tap with a ball peen hammer after welding all beads but the base or root while it is hot. (It will look like a golf ball)This is needed on cast iron etc, and is standard when welding most alum cylinder heads etc in automotive applications, helps with micro fractures.

Thanks guys! Your willingness to help a old retired hobby welder is surely appreciated. Thanks to Jody for providing this amazing forum!! It will probably be a week or so before the 5183 rod arrives so I will be quiet about this project for a while. Just one more question I haven't gotten a answer to. What temperature should I heat the part to before I begin the weld?? I have a temperature gun I use for powder coating parts. I use a old kitchen over to cure powder and their temperature controls are notoriously inaccurate. It takes 375-400 degrees to cure most powders.

Jim

Hi guys I'm jumping back in here after my confuser has been in the revolt mode for a while. Jody just posted up a pretty good video on AL casting repair. A VERY important thing he covered is to stop the crack by drilling the end of it. On the preheat thing,, I would heat to around 450 plus or minus. What the preheat attempts to do is take the expansion movement of sudden heat shock out of the casting. Just as important is to cool it as slowly as possible.

Rick_H wrote:Id also recommend lightly peening the alum as well

A very effective way to stress-relieve a weld via "peening" is to pound the crap out of it with a pneumatic needle-scaler. While hammering/planishing will work, it is very hard to get in to corners, while a scaler will get into the tightest spaces.

On the other hand, if your alloy will work-harden, you have to be careful not to overdo it, as a needle-scaler is 25 little hammers beating the crap out of your weld 50+ times per second.

Steve S

On the other hand, if your alloy will work-harden, you have to be careful not to overdo it, as a needle-scaler is 25 little hammers beating the crap out of your weld 50+ times per second.

Steve S

now that is as technical an answer as i will ever need........
craig