13 replies to this topic

[Gatti]

Hi guys,

 

I'm new to welding etc

 

My question is, after tacking in a new piece like in the picture below (not my work) how do you finish it off and fill in the small spaces between the welds?

 

Do you just keep on tacking until it forms a solid weld along the join??

 

I know you shouldn't do long welds as it can warp the metal.

 

 

Attached Files

•  Butt Weld.jpg   126.57K   10 downloads

[CI 0308]

Yes correct but ensure you have enough penetration so the the weld is not just a blob sitting on top of the metal. Place a tack in one spot then move to another area so as not to get too much heat into the metal. Also use a wet rag to keep it cool as you go. I also use a piece of copper busbar behind as well to take some heat away.

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[TerrA LX]

Depends on oem finish, plus, some require stitch welding over fully welding.

To answer it, you may keep tacking slowly to reduce heat warping but the norm, if fabricating is to run continuous welds with the correct penetration.
If it is structural then uniform penetration is a must.

[Gatti]

Thanks guys

 

I need to replace a section of the floorpan and do a couple of small rust repairs so nothing too major

[TerrA LX]

technically, it should lap the original metal by about 1/2 inch... as you would see any panel that have been welded in by the factory.

[grumpy xu1]

He's talking about a but weld ! Tack it around the edges ect & then do 1" stitch welding, so you get the proper penetration, don't overlap ! & yes you can use the copper on the back. Leave a 1 mm welding gap.

[Gatti]

Thanks

 

What is the best type and thickness of sheet metal to buy for doing rust repairs?

[CI 0308]

Go to a sheetmetal shop and ask for a bit of 1mm cold rolled zinc annealed sheet for panel repairs or slightly thicker for other areas if required.

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[Gatti]

Go to a sheetmetal shop and ask for a bit of 1mm cold rolled zinc annealed sheet for panel repairs or slightly thicker for other areas if required.

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Thanks mate

[Gatti]

A friend also suggested buying an old car door or bonnet and just cutting it up to the the metal I need.

[grumpy xu1]

.8 mm is good to work with & shape mate, just ask for panel steel. & i use .6 mm mig wire !

[limo]

I always use a door, roof or bonnet from car of similar model / year for source of metal, use .6 wire as above

seems to weld easier for me as a non qualified welder

[Rockoz]

You can buy a cheap digital micrometer on Facebook from the Wish app for about 11 bucks plus a few extra for postage.

Worth it for measuring the thickness of the steel.

My local sheetmetal bloke has all sizes of sheet at good prices and will cut to size.

 

So measure up the sheet you are replacing and get the closest size.

Slightly thicker will always be the better option.

 

For buttwelding it may pay to look at investing in a TIG.

A lot easier to finish off the welds.

Tack in place with the MIG because its easier and quicker then finish with the TIG.

 

Just my thoughts anyway.

 

Cheers

 

Rob