What is keyholing?

[BillC]

In the "3&4g 7018 Ac" thread there were several referenced to the keyhole.

What are you referring to?

Thanks!

[Rocky D]

Originally posted by BillC
In the "3&4g 7018 Ac" thread there were several referenced to the keyhole.

What are you referring to?

Thanks!

I'm glad you asked that question, Bill. Keyholeing is a method of getting 100% penetration on a butt weld. I hope you can see it in this picture.

[BillC]

Originally posted by Rocky D


I'm glad you asked that question, Bill. Keyholeing is a method of getting 100% penetration on a butt weld. I hope you can see it in this picture.

Rocky,

I gather that the keyhole refers to the appearance of the root pass of an open root weld, but I cannot enlarge your photo to clearly see what you are referring to... Sorry...

Thanks,

[Rocky D]

Originally posted by BillC


Rocky,

I gather that the keyhole refers to the appearance of the root pass of an open root weld, but I cannot enlarge your photo to clearly see what you are referring to... Sorry...

Thanks,

Ok, I'll try to explain...as you start your 3g (vertical) weld, you poke a hole through the open root, so that the weld metal you are pushing through goes through to the backside of the plate, and fuses the back corner of the root opening. It makes a hole that you work up the entire length of the weld. Hence, the name Keyholeing.

[BillC]

Originally posted by Rocky D


Ok, I'll try to explain...as you start your 3g (vertical) weld, you poke a hole through the open root, so that the weld metal you are pushing through goes through to the backside of the plate, and fuses the back corner of the root opening. It makes a hole that you work up the entire length of the weld. Hence, the name Keyholeing.

Thanks Rocky,

I get the idea now... I haven't had to do anything open root in class yet. But it makes good sense and explains the appearance of the backside of the welds in all of the pictures...

Thanks again,

[Dan]

Bill C

Here is a picture of what Rocky D was trying to show you.

[Rocky D]

Originally posted by Dan
Bill C

Here is a picture of what Rocky D was trying to show you.

Yup, that's it! thanks Danny.

[BillC]

Originally posted by Dan
Bill C

Here is a picture of what Rocky D was trying to show you.

Boy, that picture clearly shows the keyhole... Thanks, Dan!

When you are laying the root pass, where is the keyhole with respect to the puddle?

Thanks!

[Chris]

Bill,
The keyhole is in front of the puddle. As you weld the molten metal of the puddle fills in the keyhole without the keyhole ever actually disappearing. It is tricky at first but as you will probably find out in class the more you practice it the better you get (except on those days when you drink too many Dr Peppers before class).I hope this helps some.
Chris

[Rocky D]

Originally posted by BillC


Boy, that picture clearly shows the keyhole... Thanks, Dan!

When you are laying the root pass, where is the keyhole with respect to the puddle?

Thanks!

The keyhole is the puddle. Once you see it, you will understand, and it's not that hard to do. What's hard, is trying to explain it on the internet! :D Ha Ha!

[Chris]

Rocky,
Your right. I always thaught of the keyhole as JUST the hole in the puddle. But it is the puddle with the hole, ah haaa. I don't know if I'm making any sense but I can't wait to make my next root pass!
Chris

[DocSavage]

When taking my class we learned how to use a torch to butt weld. We were shown how to wait for what the instructor called the key-hole to form before dabbing the rod in.

Is this the same thing that is going on here?

[Roger]

Yes, get same key-hole and easier to see when gas welding.

[Rocky D]

While we're on the subject...I remember a time I was told we had to produce a weld in .090" titanium using automatic plasma welding, using the keyhole technique, with no filler material! I had a flatbed automatic machine outfitted with a hand plasma weldng torch. The plasma torch operated with two gasses, I don't remember what they were...I was a young welder, and had only brief experience with the automatic, but supposedly that was enough, since we had the test parameters from Boeing who was doing this on a regular basis.

I set the machine, the gas, speed, heat, and everything according to the specs and I couldn't get it to keyhole! I had a stack of machined plates, that were process cleaned, but still it wouldn't weld. I would burn through, and it wouldn't form the keyhole. I wasn't till after fighting it all day I decided to deviate for the params. I don't remember what I didnow, but I got it to keyhole weld, and what a beautiful weld! With no filler, the weld was .100" wide and had a slight convex reinforcement on both sides! I guess my point here, is that parameters set up on one machine don't necessarilly work for every machine....That holds true in any method of welding...

It is the results that governs the procedure.

[BillC]

Originally posted by Rocky D

It is the results that governs the procedure.

Wow, was Machiavelli a welder???:)

[shaky]

I have been trying NOT (emphasis) to do this for years ...... on car body panels! Oooooops