need some aluminum help...

Date 07-06-2010 01:30 Edited 07-06-2010 01:36

I usually use accetone after buffing it out or grinding. Try to stay away from rock discs that will leave peices of the disc in the base material. I use green-back discs most of the time on aluminum. Most of those tankers have all kinds of junk in the cracks when they get them. Take a rose bud and heat it up and let it cool off a couple times to help burn out some of the junk in there.I tig weld most of my repairs on stuff like that because of the cleaning action you get. Really cant get around just putting a patch on them most of the time.

By burleigh26 (**)

Date 07-06-2010 01:36

I had the same problems welding on alum. crew boats. they are pitted and they soak up the salt and grind from the gulf. not sure on any chemical to use but the way i figured was grind the spot about half the thickness of the material and weld it, doesnt matter what it looks like. then grid it out again and reweld it. some times it may take up to 5 times before it starts to weld correctly. i started out tring to figure this out and would blow a big hole. even if you weld it the first time a little cold, you have to build a barrier first. it works, kinda a hassle but thats the way i know how. and drain all the liquid out first, aluminum want weld worth a crap with any liquid on the material.

By Tommyjoking (****)

Date 07-06-2010 22:06 Edited 07-06-2010 23:47

Another thing you might try is using carbide rotary files on a die grinder....it will not leave any kind of residue and it helps being at being precise when removing a defect. 90% isopropyl alcohol and acetone are both good for final cleaning....you might need heavy degreasers or even a paint stripper to start with. You can guarantee the inside surface of the tank is corroded and filthy....so if you are melting the base metal enough to wet the inside (of the tank) you will never be able to fix it....it will pull all the more contamination in. I hope you are using GTAW because that can help you float/see junk up in the puddle to be removed + it makes it easy to see contamination.....if you are using GMAW you are shooting yourself in the foot because it will just pile weld deposit around the contamination.

Good luck with it
Tommy

By welderrwc72 (**)

Date 07-07-2010 00:01

Man o man what a pain in the rear!!! Got the whole patched, leaks fixed as far as I could tell. Got the truck pulled off the pad and parked it, told em it was done and they said " oh yeah, can you replace the sump in the rear also"!! Damnit I love having work, But one of these days Alice!! So I cut another big whole in it and here we go again

By makeithot (***)

Date 07-07-2010 15:12

There is a product called Alubright not sure if that is spelt right but it is an acid made for cleaning aluminum and works real well. But if you have not steam cleaned the tank before starting the weld repair all the acid in the world isn't going to help much because the oil will just run down to the crack as soon as it gets hot. I would also suggest tig welding the crack first before putting the patch on gives you a better chance of dealing with the porosity and impurities that will be present.

By welderrwc72 (**)

Date 07-08-2010 00:58

I wish I could post a picture of these things!!! Ya theve all been steamed out, because of of the explosion factor of em. just no easy way around em, grind grind grind weld grind grind weld...

By MDG Custom Weld (***)

Date 07-09-2010 16:44

I do a lot of repair on aluminum dumps used to haul anything farm related...lime, fertilizer, grain, manure, ect. Most of these trailers were used and abused long before they got life on these farms. You never really know how "bad" the little repair might be until you grind, wheel, solvent, heat up (usually not needed), and then finally strike an arc. Most of the stiffener ribs and any unwelded seam are full of crap that does not like to be welded. Once you start welding, what ever is in deeper or under your weld area will start getting sucked in, you’re completely in line with your grind weld grind grind weld grind weld grind grind weld.

By bozaktwo1 (***)

Date 07-11-2010 13:04

I would think that the alloy you're working with makes a big difference in your repair procedure as well. 6061 will weld differently from 5052; also, whatever the material is exposed to will have different adverse effects on the properties of those alloys. Do you know what causes the cracks? How are you finding the limits of your base metal integrity? If you're just slapping patches over cracks, that isn't going to do anything for very long. I would at least find the ends of the crack and drill holes to get them stopped. That will give the patch a fighting chance of lasting a while. Have you considered doing a crop and chop instead of just welding up the crack?

By rig welder6 (**)

Date 07-11-2010 18:45

are you tiging or wire? all the alum i have fixed from boats to tankers, flatbeds, to alum on a rig grind-weld-grind-weld but i have had the best luck with wire and 4043 alloy hope it helps

By welderrwc72 (**)

Date 07-13-2010 22:18

I believe the material is 4043? I think. Weve tried everything on these transports, from drilling the cracks to cutting it clear out and new material welded in its place. The problem is if you fix a crack here, it will crack 6 inchs over. theyre just trying to take highway transport trailers down nasty rough oil lease roads and the bouncing, vibrations, and oil mixed with who knows what, breaks them apart. Ive talked em into just putting new bottoms the whole length of the trailer in them. It seems to take all the guess work out of it. Its alot more work for me, but good thing I contract by the hour...