tigging 1/2 " alum question

[rb455ho]

Hello all, quick question regarding 1/2" aluminum. Set up syn 350, He-Ar mix, 5-32 W 2% thor, 5-32 4043 filler rod. T- joints, lap joints, butt joints, all work great with good penetrations and uniformity. I am having some problems filling in a hole that was mis-drilled or part of a slot that was mis-milled. Can anyone advise me on a good technique for filling these voids in 1/2" Al.

Thank you
Rob


P.S. Happy Holidays!!!!!!!!!!!!!!

[wrench3047]

I was told one time that you should use a backing of steel or copper on al and al or copper for steel. For something that thick you might want to get as much as you can then go from the back or bevel out the hole to get the torch in there better then fill it in with a backing.

[arcdawg]

copper backing is a good idea.........and so is preheating the peice.........and possibly enlarging the hole a little bit and if you can get it on both sides of the peice........

dawg

[rb455ho]

filling the hole is difficult

thanks for the info guys. I will give your suggestions a try and let you know how it turns out. Doing the joints is a cakewalk compared to this.

Thanks
Rob

[Blown S-10]

fill the void with a piece that filles the hole/whatever. then weld that in.

[rb455ho]

plugging

I agree that plugging is the correct option from all aspects, strength, ease, appearance, etc. This guys does not want to do that. I told him it had to be done that way for the above reasons, he looked at me funny. I said oh well that's the only way I can do it.

Thanks all for your help

Happy Holidays
Rob

[Scott T]

An easy way to fill the hole would be to counter sink it, would give you access to the bottom without any problems. You could go half ways from both sides or all the way down from one side. Quick fix with out a headache. Scott.

[rb455ho]

countersink

The void is actually a slot that is 1.25" by 5/8" by 1/2" thick 6061-T6 AL.
I am going to make some plugs tommorow. I will try the countersink option on a piece of scrap. Thanks for the input.
Happy Holidays

Rob

[HAWK]

I prefer carbon for a backing when filling holes in aluminum. It does not draw the heat like copper or other metals. Old motor brushes work well.

[Blown S-10]

i am a bit confused as to what you are trying to do, a hole and/or a slot. a pic would be worth a lot, as well as what the piece is used for.

[rb455ho]

both

blown s-10

The piece in question is a 6"x4"x1/2" aluminum angle. It has slots and holes and tapped holes. The two slots were milled in the wrong spot and one of the holes was drilled in the wrong spot. It is part of a motor mount system for a Yanmar diesel boat engine. My friend has a machine shop that makes these. Usually all I do is weld a pinned gusset in the middle and then it gets powder coated. However, he screwed up a few and is trying to salvage them. Hope this makes sense
Thanks

Rob

[Blown S-10]

ok, i would, get some 5/8" round bar, or better yet 1/2" x 5/8 flat bar. cut a piece about 1 1/4" long, then round the ends to match the slot ends. then weld that in on both sides. then grind it flat.

cut a piece to plug the hole, weld that on both sides. this shouldn't need much filler.

good luck, shouldn't be too hard. let us know how it goes.

[weldmup]

Hello all, quick question regarding 1/2" aluminum. Set up syn 350, He-Ar mix, 5-32 W 2% thor, 5-32 4043 filler rod. T- joints, lap joints, butt joints, all work great with good penetrations and uniformity. I am having some problems filling in a hole that was mis-drilled or part of a slot that was mis-milled. Can anyone advise me on a good technique for filling these voids in 1/2" Al.

Thank you
Rob


P.S. Happy Holidays!!!!!!!!!!!!!!

Get a Countersink and open the hole up like a V Groove and use Copper backing when you fill it.You will probably have to flip it over after filling the hole and blend the penetration in.

[wrench3047]

Now that I know it's not just a little 3/8" hole I agree with making a plug for it. That would take a minute or two to fill in and probly wouldn't have to taper the hole if you did weld it shut. Probly take little bit of filler rod also.

Are the slots milled in the right spots now.

Mele Kalikimaka

[Andy249]

rb455ho,

If I were your friend I would scrap the pieces and put it down to experience and ensure it doesn't happen again!! I would have a go at filling the slots out of interest but I don't think it is a very economical alternative to just scrapping the pieces, unless of course the prices for aluminium over there are very much inflated compared to prices here in Australia.

If it were me fixing it I would grab the MIG, plug the hole, flip the piece over, backgrind and prep the reverse side and put a capping run in. Sand it all back and it would be sweet. Because the angle isn't very big I probably wouldn't worry about preheat and all that, my bet is that as you get further through the weld the piece will heat up more than enough!!! Hawk's idea with the carbon backing is an excellent idea, might have to implement that one on a few of my own projects, aluminium is a big enough heatsink without a copper backing strip to add into the equation!