Author |
Message |
deltabrent Samba Member
Joined: August 22, 2013 Posts: 165 Location: Alberta
|
Posted: Wed Sep 28, 2016 1:12 pm Post subject: Lap welding with a MIG? Questions and tips? |
|
|
I'm starting in on body work on my bus. The front passenger floor patch where it overlaps with the wheel arch.... There is a lap there. I drilled holes through the patch panel where it over laps to weld into, that I can grind smooth. Not really working well. They don't weld tight together and little less than half don't hold. Should I just run a weld along the edge and forget trying to match to spot welder from the factory? Or am I doing something wrong? I'm painting both inside surfaces before hand then when I drill the hole it exposes bare metal to weld to. |
|
Back to top |
|
|
crofty Judas of the North
Joined: August 09, 2000 Posts: 19672 Location: Land of Whine and Phonies
|
Posted: Wed Sep 28, 2016 2:13 pm Post subject: Re: Lap welding with a MIG? Questions and tips? |
|
|
screw the two panels together with sheet metal screws then try welding. You can fill the screw holes by plug welding them. _________________ Your Vanagon sucks, Stop waving at me.
HamburgerBrad wrote: |
I slept on crofty's tent once. I passed out drunk from two bottles of Everett's brother's wine. |
|
|
Back to top |
|
|
Joey Samba Member
Joined: August 12, 2005 Posts: 5366 Location: Nova Scotia - Canada
|
Posted: Wed Sep 28, 2016 2:18 pm Post subject: Re: Lap welding with a MIG? Questions and tips? |
|
|
Probably getting contamination from the paint. Try using a weldable primer. Make sure the two parts are as tight together as possible. _________________ Joey
‘60 Kombi - '74 Bus - '79 Panel - '65 Beetle |
|
Back to top |
|
|
deltabrent Samba Member
Joined: August 22, 2013 Posts: 165 Location: Alberta
|
Posted: Wed Sep 28, 2016 2:47 pm Post subject: Re: Lap welding with a MIG? Questions and tips? |
|
|
OK I think weldable primer is in order! Nothing else is going to work.
And screwing them together makes sense.
I'm going to seam seal this one from below and move on but thanks. |
|
Back to top |
|
|
Eric&Barb Samba Member
Joined: September 19, 2004 Posts: 24733 Location: Olympia Wash Rinse & Repeat
|
Posted: Wed Sep 28, 2016 2:49 pm Post subject: Re: Lap welding with a MIG? Questions and tips? |
|
|
Possibly you need to turn up the heat and maybe turn down the wire feed. It needs to kind of BUZZ sound like bacon frying on a very hot pan. _________________ In Stereo, Where Available! |
|
Back to top |
|
|
deltabrent Samba Member
Joined: August 22, 2013 Posts: 165 Location: Alberta
|
Posted: Wed Sep 28, 2016 2:59 pm Post subject: Re: Lap welding with a MIG? Questions and tips? |
|
|
A friend locally said to hit the weld with a big hammer while it's still hot and it will flatten them together tight. Worth a shot! |
|
Back to top |
|
|
campingbox Samba Member
Joined: November 14, 2000 Posts: 10196 Location: Petaluma, CA
|
Posted: Wed Sep 28, 2016 3:10 pm Post subject: Re: Lap welding with a MIG? Questions and tips? |
|
|
How big of a hole are you drilling? |
|
Back to top |
|
|
deltabrent Samba Member
Joined: August 22, 2013 Posts: 165 Location: Alberta
|
Posted: Wed Sep 28, 2016 3:27 pm Post subject: Re: Lap welding with a MIG? Questions and tips? |
|
|
1/4" or so? |
|
Back to top |
|
|
campingbox Samba Member
Joined: November 14, 2000 Posts: 10196 Location: Petaluma, CA
|
Posted: Wed Sep 28, 2016 3:37 pm Post subject: Re: Lap welding with a MIG? Questions and tips? |
|
|
deltabrent wrote: |
1/4" or so? |
1/4" is plenty. |
|
Back to top |
|
|
busdaddy Samba Member
Joined: February 12, 2004 Posts: 51127 Location: Surrey B.C. Canada, but thinking of Ukraine
|
Posted: Wed Sep 28, 2016 3:39 pm Post subject: Re: Lap welding with a MIG? Questions and tips? |
|
|
deltabrent wrote: |
A friend locally said to hit the weld with a big hammer while it's still hot and it will flatten them together tight. Worth a shot! |
Only if there's something heavy behind it to back it up.
1/4" is lots but do make sure you are penetrating the lower layer and not just refilling the upper hole. _________________ Rust NEVER sleeps and stock never goes out of style.
Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!
Слава Україні! |
|
Back to top |
|
|
deltabrent Samba Member
Joined: August 22, 2013 Posts: 165 Location: Alberta
|
Posted: Wed Sep 28, 2016 3:55 pm Post subject: Re: Lap welding with a MIG? Questions and tips? |
|
|
When I did the sill on my cargo door I did 1/8" and it didn't work at all. I drilled them all out and redid them bigger and had but better results. The front floor hasn't worked as well though. |
|
Back to top |
|
|
Eric&Barb Samba Member
Joined: September 19, 2004 Posts: 24733 Location: Olympia Wash Rinse & Repeat
|
Posted: Wed Sep 28, 2016 4:21 pm Post subject: Re: Lap welding with a MIG? Questions and tips? |
|
|
deltabrent wrote: |
1/4" or so? |
For a beginner you might want to go bigger, maybe to even 3/8". You want to light up the weld on the body first and then weld the hole edge of the sheet metal you are putting on to that lump of weld on the body, all in one motion. _________________ In Stereo, Where Available! |
|
Back to top |
|
|
earlywesty Samba Member
Joined: May 03, 2004 Posts: 2357 Location: In the woods, Ontario
|
Posted: Wed Sep 28, 2016 4:42 pm Post subject: Re: Lap welding with a MIG? Questions and tips? |
|
|
Sounds like your welder isn't set up/adjusted right. You likely are not getting penetration with your welds if they are coming loose. Try turning it up a bit. Should be getting a nice crackling sound for a good weld. |
|
Back to top |
|
|
deltabrent Samba Member
Joined: August 22, 2013 Posts: 165 Location: Alberta
|
Posted: Wed Sep 28, 2016 4:47 pm Post subject: Re: Lap welding with a MIG? Questions and tips? |
|
|
OK I'm getting convinced to drill these out and do it again! Maybe try turning up the voltage. Thanks. |
|
Back to top |
|
|
Mr. OGPaint Samba Member
Joined: September 24, 2010 Posts: 823 Location: Oregon
|
Posted: Wed Sep 28, 2016 7:10 pm Post subject: Re: Lap welding with a MIG? Questions and tips? |
|
|
Sounds like it needs more heat. You need shielding gas to get any kind of good results also, otherwise my advice is to not even bother. Also, when doing rosette/plug welds cleanlines, prep and being well clamped together are important as others have stated.
A quick tip, go watch some YouTube videos of panel welding, in particular listen to the sound you hear from other people's welding. Then go practice on some scrap metal that's a similar guage to what your working on. play with your welder settings until you can duplicate a good sound, before you even worry about how the weld looks. Leave the bus alone until you figure out what's going wrong....there are a lot of variables and a lot of damage can be done _________________ https://instagram.com/mr.ogpaint
-
Patrick Hall |
|
Back to top |
|
|
Enkiel Samba Member
Joined: October 21, 2004 Posts: 2771 Location: Quebec, Canada
|
Posted: Wed Sep 28, 2016 7:13 pm Post subject: Re: Lap welding with a MIG? Questions and tips? |
|
|
what kind of welder you got? _________________ 1964 Turkis Flipseat |
|
Back to top |
|
|
dawerks Samba Member
Joined: September 15, 2010 Posts: 2349
|
Posted: Wed Sep 28, 2016 10:46 pm Post subject: Re: Lap welding with a MIG? Questions and tips? |
|
|
Practice on two pieces of similar metal not on the bus. You should be able to melt a hole from top to bottom with just the welder without drilling a hole. If you can't do that, not enough power, contamination or wire speed is too much.
(Also hold the nozzle closer to start the weld). Er, I'm just assuming you are using a Mig welder here. _________________ "There is only one sin; disconnection from self." |
|
Back to top |
|
|
cru62 Samba Member
Joined: December 31, 2002 Posts: 4117 Location: Margaritaville.....24/7
|
|
Back to top |
|
|
bvolks Samba Member
Joined: April 26, 2004 Posts: 845 Location: New Brunswick, Canada
|
Posted: Thu Sep 29, 2016 3:03 am Post subject: Re: Lap welding with a MIG? Questions and tips? |
|
|
I bought one of these a few months back but haven't tried it yet. It looks like it would make doing stuff like that a bit easier and is relatively cheap.
http://www.eastwood.com/spot-weld-kit.html _________________ 1985 Diesel Jetta Coupe (temporarily retired at
756,000 km)
1971 Doublecab project
1995 Golf CL
1974 Beetle
1978 Westfalia |
|
Back to top |
|
|
Bulli Klinik Samba Member
Joined: January 16, 2005 Posts: 2078 Location: Bulli Klinik, Colorado Springs
|
Posted: Thu Sep 29, 2016 8:01 am Post subject: Re: Lap welding with a MIG? Questions and tips? |
|
|
Make sure that you're drilling all the way through the upper panel and exposing bare metal underneath. I like to really crank up the welder to rosette weld. I use a 220 V MIG, 175 A, turned up to about half it's power. (C setting on a Lincoln). I snip the wire, then put the wire in the middle of the hole you drilled, holding down the panel with the edge of the copper shielding gas nozzle. This gets the full blast of the shielding gas around the weld. Pull the trigger and don't move the weld too much, just lead it around to the edge of the hole until it fills. If it blows out the bottom, adjust your trigger technique and give it short blasts. The weld should flow out and not be a big mound.
Just an FYI; Weld through primer is somewhat of a misnomer. If you're rosette welding a plug, the paint must be removed if you want a clean, strong weld. I hate using that stuff as it takes so long. But it's easier than replacing the panel again! _________________ I've never met a Bus I didn't like.
Mike K
Bulli Klinik
Colorado Springs |
|
Back to top |
|
|
|