Practice Butt Welding. Inner Arch Action

[scott180gtb]

I have borrowed a mates welder to have a play and see if I have got the skills to weld some repair patches into my floor. I am a welding novice! I can use the MiG at work but it's only for emergency repairs to plant machinery. Have a look at the pictures. They are good for a laugh. Can any welding gods out there please give me any free tips or advice other than not giving up my day job I would greatly appreciate it

For the practice runs I have been using an old tailgate. I have basically cut out sections and had a play trying to weld then back. It took me a whole day to set up the welder. Its to easy to blow holes or lay a log of weld onto the work piece. Some early examples




I have been struggling with getting the weld to penetrate fully. I can lay lots of bird s*%t but spent another day concentrating on getting a fully fused well. At this point I must say I was not using an air line to cool the welds so the heat was dissipating and causing the metal to loose its shape




After another day I think I am getting closer. I found that if I take it really slow I can get a good weld but get carried away and forget to cool it down. That is until you grind it down an find hairline cracks. Up with the heat? I'm putting this down to the weld not fusing due to the lack of power. Advice?




This is the finished article after attacking it with an angle grinder. I managed to warp the metal again with too much heat from the grinder. I think I need some sort of radial grinder to finish off.





I think the key is in the fabrication. Big gaps mean lots of filling which means lots of heat. Any advice or abuse is welcome (come on Matt) I'm going to try and fab up sections with less of a gap and see if that helps. I will stick some more pictures tomorrow.

[beardymat]

Not too shabby Scott, once you have the plate tacked in and cooled feel for a step between the two pieces with your finger and use a small screwdriver to gently tweek it until they are flush. Also aim to weld closer to the previous tack so they overlap slightly and keep it cool and keep checking how flush it is.

when grinding i use a seven inch flexible disc usually in 60 grit and i keep it moving to prevent heat build up, also use the blower to keep it cool. for the hard to reach areas i use a belt sander again with 60 grit belts. Dont keep bashing away with worn out discs as that will achieve little other than more heat build up.

A bit more practice and you will be ready young jedi Might have to give you a job as i could do with some help.

[jbh]

reading this with interest. just bought a sip 130 turbo mig welder and im looking to teach my self to weld. so is there any tips youd share Mat ?

[Dezzy]

If he is a Yedi Matt are you Yoda?

Nice new plate is great to practice on 20 year + cars are a different story. Seam sealer fires are fun as are the fumes.

Looks a good first attempt to me. I fooking hate welding cars.

[scott180gtb]

I think I need to invest in consumables. Matt were do you get your gear from? I know I keep threatening but I'm going to have to pay you a visit and check out tool store

[Dezzy]

reading this with interest. just bought a sip 130 turbo mig welder and im looking to teach my self to weld. so is there any tips youd share Mat ?

Set the welder high James till it blows through then turn power and feed down till it's just not blowing through and sounds like frying backon.

Then use lots of overlapping tacks to weld body pannels. Move around the welding area to keep temps down.

That's what I do but I am no expert. Matt will tell you better than me.

[Andy325i]

Watching with interest

I did a welding course ages ago, as said welding clean metal is far different to welding rusty old sheds, but you've done an excellent job there, looking forward to some updates soon


Andy

[beardymat]

/\ thats pretty much it Dez, no big secrets just lots of practice and patience, also make sure its clean on both sides if you have access.

I use a dedicated motor factors for my consumables but decent tools and consumables can be bought from machine mart quite reasonably or look for the clark stuff on ebay, good enough for the enthusiast.

[harry_p]

i tend to use normal grinding disks just to get the very high spots off, then go to a sanding flap disk to take it down flush, as has been mentioned, don't rush, don't press too hard, and move around so you don't create hot spots.

i have an electric power file, which with a course belt is superb for tidying up immitation spot welds in hard to reach places (where you drill a hole in the outer pannel, and weld through it to the one behind, and fill in the hole to emulate a spot weld without the use of a spotwelder )

youre definately going about practising the right way. old body pannels are absolutely the best way to practise for welding on a car. anyone can weld two lumps of exhaust pipe or nice clean thick plate together neatly on a bench. doing the same to 1.2mm steel upsidown outside is a different matter!

[DanThe]

Could do with turning the welder up a bit but looks good for practice run, get the torch angle and distance right and those tacks will improve

[scott180gtb]

I'm going to keep playing until I'm confident to try on the shell. I plan to cut out all the rot on the area's that no one will see and put some fresh metal in. Dezzy your right, I not looking forward to laying on my back/side upside down in a sex swing trying to weld in some tight inaccessible place. I'm going to leave the real man welding to Mat.

[Dezzy]

I am the 'anyone' ^ who welds exhaust pipe on a bench mate. Fook welding on cars unless I really have too!

To be honest you can't really make things any worse if it's rotten anyway so just crack on I say.

Matts always looking for bear tokens for inner arch repairs anyway.

[Chris]

Leave the power as is for the first tack. It wont have the best penetration but it will sit nice and proud. - Do one good tack in all four corners to keep the shape.

Now turn the power up one notch, and put a tack next to the first. This time you should be able to lay a blob that leans against the first and welds the next 5-7mm of metal, because you are welding onto the first weld the extra power wont burn through but will let the bit on the metal sink in a little deeper.

Do this in each corner, (but not round and round in circles, do opposites) to spread the heat out nice and evenly.

If you have any problems, burn through, miss. STOP. walk away for 5 mins. Put the kettle on and come back a little later, dont try to use the mig wire as filler, it'll just get worse.

After a little practice you should be able to do this fairly quickly but it's still not a fast technique. Take your time and dont rush things, even the bits you screw up are good practice.

Good luck with it.
Chris

[Ant]

I run a panel dolly up the inside when butt welding panels, sucks the heat straight out and minimises any distortion, not always possible but for 75% of panels, it can be done and worth the effort.

Welding looks OK dude, not easy is it ! practice practice practice , that's my only advice, best way is get stuck in so hats' off

What gas you using BTW ? Argoshield will give a cleaner weld than CO2, try and purge gas for a split second before welding, and again after you have finished the arc, again will minimise distortion/contamination

For grinding, just keep moving, stay in one place and it will heat terribly, little and often everywhere.

[harry_p]

one other thing,

if you're actually enjoying welding and think you might be doing a fair bit of it in the future, an auto-dimming mask is an absolute must have! i don't know why i struggled for so long with a fixed shield helmet, and got welding sunburn many times where i've tack welded without a helmet using the line up, close eyes, bzzzzz, open eyes, repeat over and over.

i bought a 3m speedglas one for around £100, but you can get cheaper ones which are supposed to be fine for diy use. worth every single penny every time i use it!

[scott180gtb]

Thanks for all the advice gents. Well I had a bit of waisted day today. I got about four tacks done and then ran out of gas. I was itching to get stuck in today and try out some of the advice. Ant I'm using Argoshield curtsy of work. Its going to be a week until I can rob some more. I have using a busted auto-dimming mask just to stop the sun burn. I will invest a good mask as I think I have got the bug. I used a scriber to mark out the fillit sections for a smaller gap.



Here are some examples of what the tacks looked like without gas.




I carried on to practice and improve my technique. I think I have got the hang of how and where to spot, just need some gas for a proper fused weld. If I'm honest it took me a couple of hours to work out that I had ran out of gas. Again I am a novice and part time retard. Its all a learning curve.



After grinding down you can see the lack of gas meant there was no penetration at all. I'm glad I have learnt this now rather than trying and failing on the car. Soon as a get some more gas I will post up some more of my efforts. I spent the rest of the day fabing up some pieces that I have already cut from the floor.



FAIL FAIL FAIL


I have one question. Do I weld from the inside out when repairing the floor? I'm working on a bare shell so no fuel tank carpet etc.

[Andy325i]

That looks like my attemps did a while ago with gas! You want to weld both sides and then seam sealer it to avoid a water trap.

Keep us posted

Andy

[DanThe]

You defo need gas

Weld from inside the car, once you get better you will be able to get the weld to penetrate fully and drop into the gap completely

[Wocka]

i heard you can get wire that doesn't need gas.. is that right??

[jbh]

i heard you can get wire that doesn't need gas.. is that right??

yip you can get gassles wire

[Dezzy]

It's not worth a w4nk

[DanThe]

Yeah they use it on building sites

[E30BeemerLad]

chemical metal FTW!

[Dezzy]

It would be funny if you didn't actually mean it Lee.

[E30BeemerLad]

Must be the fibreglass fumes making me say things

[Wocka]

Yeah they use it on building sites

nuff said

[Wocka]

chemical metal FTW!

pah! cornflakes packet ftw

[scott180gtb]

Lee we both know what chemical metals is good for. I don't think its fiberglass fumes

[TheHeap]

I have always been tempted to buy a welder but never know what one to buy and where the hell do you get the metal from?

[Chris]

Avoid gasless, you might as well have a stick welder for all the finesse and cleanliness you get from that rubbish.

Going back to the mask thing for a moment, i bought the cheapest auto one i could find on ebay (about £40 delivered) just to try them out with the intention of getting an ESAB one if i liked it.

And so far i cant fault it, almost a year later it's still in good shape (despite my brother in law driving over it in his Seat scrap after i welded up his heat shield)

Not had itchy eyes once and it's standard size for cover glasses.

Chris

[charlE30]

Interesting thread this, going to try and teach myself again. Thanks for the inspiration

[scott180gtb]

A quick update on my efforts. I had a slack week at work so had another practice welding some pieces into a bonnet. I managed to borrow some more gas and treated myself to a brand new mask. This is about my forth attempt at welding in a repair section. I think I have cracked how to weld when holding the wand and welding something that is on the floor. What I have struggled with is welding when sat up. I have been welding pieces into a bonnet that has been stood up. I've been trying various angles of the wand but to begin with I kept melting the wire and just laying a log on top of the work piece.




This is another attempt after several hits with the welder and grinder. Still managing to warp the steel with heat. Also I haven’t quite got the fillet flush.







I have lost count of how many times I have done this now but this is my latest attempt and by far the best. I got the playdo trick from you tube. It really helps to dissapate the heat. It's still not perfect. I had to have two goes with the welder but I think a third round would see a near invisible repair. Each one of these patches takes me about five hours.






Some more pictures of what I have been cutting out of the floor pan with the repair sections already made up. I'm close to having the courage to crack on with the unseen stuff on my shell. As long as I get a good penetrating weld then I can't make it any worse. What do you think?










One good reason to leave the guard on your angle grinder



Angle Grinder= One Finger=0

What do you think Mat? Should I carry on and have a go on the shell?

[Alex]

Ouch, work looks good

Will them miniscule holes not trap moisture? (Sorry i'am new to welding and want to have a bash welding my cabby back together) or will a light skim of filler stop that?

[beardymat]

you needs a patch on that finger scott i did that once when i was younger but on my knuckle, never bled for some reason but was awful close to the bone

That last patch looks good, a little work needed on your overlaps but still good plus these can be dabbed in after grinding. Dont worry too much about the tiny ones as a skim of filler or some seam sealer will fill them in. your patch fabricating looks good so i say give it a go, worse case scenario is that i have to cut it back out a bit bigger so go for it.

Did i give you the correct part number for those floor bungs?

[scott180gtb]

Thanks Mat

Is this the right number for the bungs 41128200462 Can you still get the black tar like sound deadening from BMW? I'm going to play a little longer before I let myself loose on the shell.