Springerdinger
memoirs of the mediocre diy mechanic
- Messages
- 435
- Location
- UK nr Southam
Just thought I would jot down some notes
Feel free to add or correct me.
Welding is a very small part of what we are trying to achieve. So dont rush to get the welder fired up.
"The more I practice the luckier I get"
A lot of hobby welders feel that you need low amps for thin sheet metal.
A point I want to make is that if your amps are too low it's harder to get the initial arc going. We blame our machines for that
It takes longer to form up a good penetrating puddle. So we stay in the same spot firing in more heat and the panel starts to distort. The instinct then is to start moving straight away so you end up with a cold weld that doesn't stick or penetrate maybe a few balls of steel or high lumpy gappy welds. Oh and splatter.
Also if your using long thin extension cables you may get some amperage drop from your mains plug. This means the chart on the welder is a little off. You may need to turn up your amps to compensate.
On the flip side too many amps and you get a wide flat weld straight away and blow through holes. Unless you move fast
Experiment with the amps.
Use the stop start trigger action as per the video in the forum tutorial.
Put your time into templates and cleaning the metal. It's time well spent. An hour of prep. Then 10 minutes of welding as a reward.
Rust, oil and underseal will ruin your day and your weld.
If you cut the first repair piece wrong. Don't try to make a patch fit. If it's got big gaps or overlaps. Start again. The end result and your patience will be rewarded.
Position, clamp, secure with magnets the panel or repair piece.
Tack the panel into position first. So it fits properly. Clamp it tight where you can.
Tacking will also allow you to form the panel around curves rather than bending metal in vices that are not curved quite as nicely.
When running beads on cars and thin panels do a small inch or 10m to 25mm run using on then off the trigger action in a constant controlled rythem. Listen to the click click if the feed as you go.
Use a brass or copper backing plate where posSible to help reduce heating the panel.
Then move to a different cold part of the panel. Or have cup of tea while it cools. This will reduce the risk and amount of distortion. Less work later.
Welding on a cold panel means less chance of blowing a hole as you start the weld.
If you blow a hole. Let it cool. Don't panic.
Then when it's cold just do a couple of very quick tacks on the edges of the hole. Let it cool. Add a bit more and slowly fill the hole using the thicker tacks to move off from. This reduces the risk of making a tiny blow hole big.
You can blow a few holes in some practice sheet and have a go at fixing them. That way when it happens. (And it will) you will be able to fix it.
After running a bead and the metal is hot you can also gently tap the next bit into shape if it's needed. Don't smack it with a lump hammer. A few basic panel beaters hammers and dollys are worth their weight in gold.
Put the dolly behind the two seams and gently tap the patch into line and shape with the existing panel.
Gently not a golf swing. Let the dolly and the hammer do the work. The hammers and dollys will help you form more realistic repairs. Rather than flat patches.
No dolly = dent.
Be gentle. Take your time. It's a beautiful thing to see light taps form metal. Make sure you use dollys behind with curves or flats that will help give you the shape you want.
Practice with 0.6 and 0.8 wire. I like 0.8 because I find it more versatile on a variety of thicknesses. On my old cars it gives me strong welds and seems to be more forgiving.
Make your own notes on amps and feed speeds so a month later your not learning all aver again.
I like to use argon/co2 mix on cars and thin sheet. Less splatter. And for me neater end result than co2 only.
I fully except cost and how much welding you might do are factors here.
Finally...
In the old days if you built a steam engine and boiler you were expected to stand by your work while it was pressure tested.
Hence the saying do you stand by you work.
So if you have welded a patch or a panel and it looks like a splatter of unpenetrated mess or it weld on rust. Don't just grind it and underseal it.
Stand by your work and start again. It's not that you failed. You just need to practice.
Don't risk other people's lives with a job you know is poor.
Did I say finally.....
A note for car repairs.
Watch the video on plug welding in the forum tutorial.
If replacing a full panel and it was spot welded then you can plug weld it as per the factory spot welds.
No need to seam weld it and distort it.
If your doing a reair or patch panel. Seam weld where you are joining to an existing panel. For example if you cut a section out of a floor pan. However you can also then spot/plug weld any areas that were spot welded in the factory as part of the patch. For example the edged of a floor pan onto the sill rail might have been spot welded but you need to seam weld where you cut the rusty hole out. Your repair is part seam and part plug welded in place. (Uk check your countries regulations).
Please add your thoughts or correct me if I'm wrong. I'm not and expert and a little knowlegde may just be a dangerous thing
Cheers
Chris.
Feel free to add or correct me.
Welding is a very small part of what we are trying to achieve. So dont rush to get the welder fired up.
"The more I practice the luckier I get"
A lot of hobby welders feel that you need low amps for thin sheet metal.
A point I want to make is that if your amps are too low it's harder to get the initial arc going. We blame our machines for that
It takes longer to form up a good penetrating puddle. So we stay in the same spot firing in more heat and the panel starts to distort. The instinct then is to start moving straight away so you end up with a cold weld that doesn't stick or penetrate maybe a few balls of steel or high lumpy gappy welds. Oh and splatter.
Also if your using long thin extension cables you may get some amperage drop from your mains plug. This means the chart on the welder is a little off. You may need to turn up your amps to compensate.
On the flip side too many amps and you get a wide flat weld straight away and blow through holes. Unless you move fast
Experiment with the amps.
Use the stop start trigger action as per the video in the forum tutorial.
Put your time into templates and cleaning the metal. It's time well spent. An hour of prep. Then 10 minutes of welding as a reward.
Rust, oil and underseal will ruin your day and your weld.
If you cut the first repair piece wrong. Don't try to make a patch fit. If it's got big gaps or overlaps. Start again. The end result and your patience will be rewarded.
Position, clamp, secure with magnets the panel or repair piece.
Tack the panel into position first. So it fits properly. Clamp it tight where you can.
Tacking will also allow you to form the panel around curves rather than bending metal in vices that are not curved quite as nicely.
When running beads on cars and thin panels do a small inch or 10m to 25mm run using on then off the trigger action in a constant controlled rythem. Listen to the click click if the feed as you go.
Use a brass or copper backing plate where posSible to help reduce heating the panel.
Then move to a different cold part of the panel. Or have cup of tea while it cools. This will reduce the risk and amount of distortion. Less work later.
Welding on a cold panel means less chance of blowing a hole as you start the weld.
If you blow a hole. Let it cool. Don't panic.
Then when it's cold just do a couple of very quick tacks on the edges of the hole. Let it cool. Add a bit more and slowly fill the hole using the thicker tacks to move off from. This reduces the risk of making a tiny blow hole big.
You can blow a few holes in some practice sheet and have a go at fixing them. That way when it happens. (And it will) you will be able to fix it.
After running a bead and the metal is hot you can also gently tap the next bit into shape if it's needed. Don't smack it with a lump hammer. A few basic panel beaters hammers and dollys are worth their weight in gold.
Put the dolly behind the two seams and gently tap the patch into line and shape with the existing panel.
Gently not a golf swing. Let the dolly and the hammer do the work. The hammers and dollys will help you form more realistic repairs. Rather than flat patches.
No dolly = dent.
Be gentle. Take your time. It's a beautiful thing to see light taps form metal. Make sure you use dollys behind with curves or flats that will help give you the shape you want.
Practice with 0.6 and 0.8 wire. I like 0.8 because I find it more versatile on a variety of thicknesses. On my old cars it gives me strong welds and seems to be more forgiving.
Make your own notes on amps and feed speeds so a month later your not learning all aver again.
I like to use argon/co2 mix on cars and thin sheet. Less splatter. And for me neater end result than co2 only.
I fully except cost and how much welding you might do are factors here.
Finally...
In the old days if you built a steam engine and boiler you were expected to stand by your work while it was pressure tested.
Hence the saying do you stand by you work.
So if you have welded a patch or a panel and it looks like a splatter of unpenetrated mess or it weld on rust. Don't just grind it and underseal it.
Stand by your work and start again. It's not that you failed. You just need to practice.
Don't risk other people's lives with a job you know is poor.
Did I say finally.....
A note for car repairs.
Watch the video on plug welding in the forum tutorial.
If replacing a full panel and it was spot welded then you can plug weld it as per the factory spot welds.
No need to seam weld it and distort it.
If your doing a reair or patch panel. Seam weld where you are joining to an existing panel. For example if you cut a section out of a floor pan. However you can also then spot/plug weld any areas that were spot welded in the factory as part of the patch. For example the edged of a floor pan onto the sill rail might have been spot welded but you need to seam weld where you cut the rusty hole out. Your repair is part seam and part plug welded in place. (Uk check your countries regulations).
Please add your thoughts or correct me if I'm wrong. I'm not and expert and a little knowlegde may just be a dangerous thing
Cheers
Chris.