Tech - Filling holes in a Bus dash

[notched]

I'm jumpin' on the tech bandwagon.

I'm no expert, by any means. But I am actually a trained welder. Not a certified welder, but trained in the sculpture department at an art school. I spent two years working on welded steel and cast concrete sculpture at PNCA. I also worked on bronze casting as well. My professor was one of the coolest people I've ever met, Manuel Izquirdo, a crotchety old Spaniard. He had taught at the art school since 1955, I believe. And was an amazingly talented man. Most of his sculpture was hollow form welded 1/4" bronze. His personal studio was one of the coolest places I've ever been to in my life.

Anyway, he was old school. He made us all learn gas welding first, then we spent some time Tig welding. But all of my work was gas welded. I have sooooo much appreciation for gas welded work. I picked up a Mig welder sometime along the way, but hope to get a set of tanks to get back to gas welding again.

Again, I'm not an expert, but I hope to give some basic explanations of filling some larger holes in sheet metal. If a hole is fairly small, maybe smaller than 1/4", you could fill this with just the weld. But something that is 1/2" or larger, you'll need some filler material. This should be close to the same gauge as the metal that you're welding it into.

I'm working on smoothing out a Bus dash for my Squareback. To start, I've used a angle die grinder to clean up the edges of the holes:









For the filler material, I like to use old German metal. This makes the gauge match easier. This is some extra sheet metal from the roof of a Squareback (actually part of the roof that was cut off the same Square the Bus dash is going into:



I like to use some paperboard for templates:



Rather than buying tag board, or something similar, I've used the inside of cereal boxes. In this case, POP-Tarts!:



I'm going to start with the circular cut out that was originally for the fuel gauge. I've placed the board behind the hole, to mark out a template:



I like Sharpie markers to mark on the template. They just work well while working in the garage. The just about mark on anything. The template ready to cut out:



After cut out (which I typically cut on the inside of the pen mark), the new template is placed onto the donor material to mark:



Once outlined, the material is ready to cut:



I'm a big fan of tin snips. I have three, right-hand, left-hand and strait. I forget which these are (I'm dyslexic, so I'd probably tell you the wrong kind anyway), but I use these the most. I'll start cutting this out in the shape of a square first, not cutting the curves yet:









After cut out, I'll start to make the shape:



(sorry for the blurry pic)



After the rough shape is cut, I then took it over to a large piece of wood to start to shape it. The tin snips tend to bend the metal a little, but this piece is pretty small, so it wasn't too bad. But, there is another reason to shape it on the wood. The Bus dash has a subtle curve to it. The filler piece needs to match the curve. One way to do this is to slightly hammer the back of the metal to get it to curve toward the hammer. I'm not pounding hard at all. This is more of a tapping:





I don't know if this pic shows it, but there is a slight curve:



I've checked it against the Bus dash periodically.

[notched]

It's ready to place into the area; the curve and shape look good:



The edges are still rough from cutting and there is paint on the metal. This needs to be cleaned off for a good weld:



For the edge, I've used an electric grinder with a metal grinding disk:



You'll notice the space around the filler material and the hole:



Ready to weld!

I'm using a welding magnet to hold it in place. The first tack weld:



This is the basic process, tack welding is key! In order to keep the metal from warping, and your bodywork to a minimum, you should use a series of tack welds. I've tried this a few ways, and what I like to do is start one tack, then one to the right, one to the left, then back to the right, and so on. I don't do this religiously, but most of the time.

More tacks:



Remember the spacing around the filler material and the hole? I can finally tell you why this is important. First of all, as the metal is welded, it moves around! If there isn't a space around the filler material, and it was a perfect tight fit, as you work your way around, the filler may move, and actually overlap once to another side. The gap will give you room. I like to make it about 1/8". If it's too big, you'll have to use too much welding material. The second reason is so that the tip of a screwdriver will fit in, as shown in this shot. You may ask, "What's that for?” Well, as you weld, the material moves around, not only side to side, but it can move up and down. By using a screwdriver, you and either move the filler piece up or down, depending which way it's shifted. This is very important to control the filler piece as you weld. You want it very close to flush with the other metal:



This is how much it started to lift up.



This is not finished. Part two soon!


++ In Progress ++

[TeamEvil/TC]

WAY COOL!

How come people don't weld from the back side, for strength . . .

then a light skim of filler on the front side, for looks?

Seems that it would save a lot of that grinding and stuff.

[vwfanatic]

tc...weld from the front and grind carefully and if you do it right, no filler needed. then you can have a bare metal dash and nobody can tell where you did the work

[Nick]

Excellent tech! One thing to make it slightly easier is to strip the donor sheet metal before you cut it. At least with the small pieces, easier then trying to hold down the piece from flying around when stripping it.

Also one thing to keep in mind, if you want to add gauges or switches to the dash, be aware of the spots you've patched up or it may be harder to have it flush mounted from the welding. So sometimes it maybe better to make the hole bigger on the dash then weld in a bigger piece back into the dash so the beads won't interfere with the new mounting instruments. Or if you want the entire dash smooth, it will be easier to cut off the entire dash instead of filling in dozens of smaller holes.

[speedfreak]

That answers alot of questions! thanks for the tech! so, when it comes to tacking your pieces in, and using a mig, how do you keep from blowing holes? I have my mig set on the lowest setting and my gas at 30 and I still blow holes. does the fact that the metal is older have anything to do with it? If I don't blow hole then sometimes my welds just sit on the top and don't penetrate at all. I know it has alot to do with practice and settings, but damn it starts to get frustrating after awhile.


Larry

[TeamEvil/TC]

"no filler needed . . . "

God, I'll NEVER get that good. Never, ever.

[RyanB]

Awesome Phillip! Lookin great. I am too scared to use a mig on thin sheet like that so I use my O/A setup.

~Ry

[notched]

<div class='quotetop'>QUOTE(TeamEvil/TC @ Mar 7 2006, 05:26 AM) Quoted post</div><div class='quotemain'>
How come people don't weld from the back side, for strength . . .

then a light skim of filler on the front side, for looks?

Seems that it would save a lot of that grinding and stuff.
[/b][/quote]

That's a pretty good question. In this case, I have the dash cut from the Bus, obviously. So I could have done that. The main reason, I think, is access. If this were a dash in a car - any dash - you would have to weld upside down. It's really hard to do. This method would work on any hole, for example, the holes where a door handle would be. It's tough to weld inside of a door, but the outside is accesible. Best answer I can give you. Plus, like Dan said, the goal is all weld. We'll see how close I get to that in Part Two...

<div class='quotetop'>QUOTE(Nick @ Mar 7 2006, 06:20 AM) Quoted post</div><div class='quotemain'>
Excellent tech! One thing to make it slightly easier is to strip the donor sheet metal before you cut it. At least with the small pieces, easier then trying to hold down the piece from flying around when stripping it.

Also one thing to keep in mind, if you want to add gauges or switches to the dash, be aware of the spots you've patched up or it may be harder to have it flush mounted from the welding. So sometimes it maybe better to make the hole bigger on the dash then weld in a bigger piece back into the dash so the beads won't interfere with the new mounting instruments. Or if you want the entire dash smooth, it will be easier to cut off the entire dash instead of filling in dozens of smaller holes.
[/b][/quote]

I wish I would have sanded off the paint first, for that exact reason. Thanks Nick! Great point that I forgot to mention.

Great point on the new instruments! I have something cool in store for the instruments on this dash...

<div class='quotetop'>QUOTE(speedfreak @ Mar 7 2006, 06:45 AM) Quoted post</div><div class='quotemain'>
That answers alot of questions! thanks for the tech! so, when it comes to tacking your pieces in, and using a mig, how do you keep from blowing holes? I have my mig set on the lowest setting and my gas at 30 and I still blow holes. does the fact that the metal is older have anything to do with it? If I don't blow hole then sometimes my welds just sit on the top and don't penetrate at all. I know it has alot to do with practice and settings, but damn it starts to get frustrating after awhile.


Larry
[/b][/quote]

I am working with a Lincoln MIG welder. I think it's a Lincoln 100 - can remember exactly. It works perfect for sheet metal. On the inside of my welder, there is a great chart to determin settings for different sheet metal guage, and whether or not gas is used. I'm using 75/25 gas, and it works great. I'm using very small wire, I think its .023 - this makes a big difference in the weld. The .030 (I think that's the next size up) doesn't work well. You may try changing this. Remember to change out the tip as well.


<div class='quotetop'>QUOTE(RyanB @ Mar 7 2006, 08:09 AM) Quoted post</div><div class='quotemain'>
Awesome Phillip! Lookin great. I am too scared to use a mig on thin sheet like that so I use my O/A setup.

~Ry
[/b][/quote]

I'm hoping to get a oxygen acytelene set up soon. Gas welding is soooo much more controllable, IMHO, compared to MIG

There are two things that I haven't covered, hammer welding - just because I don't know how to do it properly. I need to learn more about it.

And using Easy Grind wire. I'm still looking for a spool of this to try.

Stay tuned for Part Two!! (Hopefully I have time this weekend!)

<div class='quotetop'>QUOTE(speedfreak @ Mar 7 2006, 06:45 AM) Quoted post</div><div class='quotemain'>how do you keep from blowing holes?[/b][/quote]

Just thought of something. Are you getting holes with only tack welds? Or a bead?

[Hebster52]

Exellent work!

To continue the topic, here is a link to a cool video on How-to-Ledfill. [img]style_emoticons/<#EMO_DIR#>/chillin.gif[/img]
http://www.voodoo-people.com/~daz/mu...ull@hugo14.wmv [img]style_emoticons/<#EMO_DIR#>/thumbsup.gif[/img]

[speedfreak]

The .030 is probably some of my problem then. I'll switch to the smaller wire and see how that goes. I am using a Lincoln 175 with 75/25 mix also. Thanks Phillip [img]style_emoticons/<#EMO_DIR#>/thumbsup.gif[/img]


Larry

[Jon]

for some reason I only see the HTML text for the images ? [img]style_emoticons/<#EMO_DIR#>/Idunno.gif[/img]

Kinda sucks 'cus I am really interested. Maybe just an off night for the server I am connected to.

I too love Gas welding, done very little of it, but its awesome. I own a torch too, just need the tanks.

I'l check back in a bit to see if the pics will load on their own, otherwise I'll have to do it manually.

[notched]

Fixed the images. I did some spelling editing in Word, and it did something to the image tags...

[Jon]

Pretty much how I do it with a mig. Great step by step, with pics. [img]style_emoticons/<#EMO_DIR#>/thumbsup.gif[/img] I love that these are being done. No we can reffer Newbies to specific threads. [img]style_emoticons/<#EMO_DIR#>/funny.gif[/img]
I use cabinet magnets sometimes as well. If its a small one.
I also will make cut a strip of sheetmetal with the circle almost cut out at the end for really small holes. Get a few tacks and then break it off.
Another thing I do sometimes for a template is use a piece of Duct tape and tape it over the hole, then take a screwdriver handle and kinda rub the edges a bit to score the tape, peel it off, stick it to the metal and then cut it out. Can use other tapes its just that I can always find the Duct tape, can never find the others when I need them. Works really good for odd shapes or ones you can't get tto the back of.