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General Information => Upgrades (non engine related ) => Topic started by: silvertdi on December 29, 2007, 10:13:24 pm
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Anybody seam weld or stitch weld the chassis? I'm thinking about doing the radiator support and the underbody. It will definately stiffen things up, but I've read that they could fail catastrophically. Any input? Thanks.
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why would it fail? i did my super beetle years ago and it is defintely stiffer than stock. did it all with a torch too. messy but fun.
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the only failure i see is not treating or sealing the metal from moisture after the process is done! anotherwords rust is the word a chemical reaction when water dries on steel! oxydation,steel is biodegradable!
another possible faliure is using improper welding technics , oxcy accetelyne ,braising is not recomended for use on vehicles from around 74,75 and newer because of the introduction of HSS (high strength steel) the heat produced from a torch takes out the temper or strength of the steel!
MIG or spotwelding is the recomended process you don't want to but alot of heat in the part your welding it just takes away the strength!
thanks Duane
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I had read that if the weld wasn't of a high quality, and a crack started, it would migrate the length of the weld and spell trouble. I read that the autocross folks do it when the rules allow. I'd just like to strengthen the areas where I jack the car so it doesn't look so bent up and ugly.
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well behind every weld there is a welder so the quality of the weld depends on thier knowledge and skill! i've done a little welding in my day! what area are you planning to beef up? i may be of assistance to ya and could tell you if it can be done or not?
send me a P.M.
thanks Duane
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bikboostedtruck you are right of course about the newer steels. in the past i would have had no problem using a torch but things have changed. i welded up my beetle almost 30 years ago.
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bikboostedtruck you are right of course about the newer steels. in the past i would have had no problem using a torch but things have changed. i welded up my beetle almost 30 years ago.
well just so you know i was not trying to shun you with that process you did nothing wrong! years ago thats how they did body work! used a torch process was called heat shrinking and also the torch was used for lead fill till it was replaced with light weight filler resins! the metal on your old bug was thicker like 22gage and the newer steels are 16or18 gage
and i still remember all this from college!
thanks Duane
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So is this something you could do with home welding set-up like you would find at Canadian Tire/Princess Auto, etc?
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isnt sheet gauge size a decreasing thing, like 22 gauge is thinner than 16.
anyway - never torch weld the body or chassis, you end up with a soft spot,
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So is this something you could do with home welding set-up like you would find at Canadian Tire/Princess Auto, etc?
i'm not certain what canadian tire has? cause i live in the states someone should chim in that knows?
and Zulfigar correct me if i'm wrong it's been a while since i worked with gage sizes? i can be dislexic some times i'm sure you know what i mean?
older is thicker and newer is thinner!
thanks Duane
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Gauge sizes:
http://www.engineersedge.com/gauge.htm
I read in a hot rod type mag years ago not to weld the seams on a factory stitch welded chassis because the factory had designed the weld locations for the stresses the chassis would see, and if you welded the seams, you could move the stresses to areas that were not designed for them - leading to failure. No proof or background was given. My personal opinion is that most factory welding is done as stitch welding primarily to reduce cost, not because someone took the time to move weld locations around in a simulator program to find the ideal location. As mentioned previously, most failed welds have much more to do with the welder's technique and expertise.
One multiprocess machine:
http://www.millerwelds.com/products/multiprocess/shopmate_dx/
This one can't do MIG, but sweet size:
http://www.millerwelds.com/products/tig/maxstar_150_sth/
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ooohh they have gone down the last time i looked was a couple years ago they were in the 3,500.00 starting range for a multy process! sweet!
that chart clairifys my dislexic butt!! thanks
thanks Duane
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This one can't do MIG, but sweet size:
http://www.millerwelds.com/products/tig/maxstar_150_sth/
ahhh i got a welder in the garage simular to to one above and i never realized it could do TIG! all i need are the attachments! SWEET!! im in buisness now! i've been wanting to weld aluminum!
thanks Duane
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truck - yeah older were thicker,
Me and a couple of my mates are taking welding classes from this real old timer, we've all chipped into buying a used mig welder, All the welders here use the old oxyacytylene torch and wire,
this old geezer used to be head welder in Pakistan Steel, so he knows his business like no-one else,
I would end up with my yard n garage looking like a workshop.
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ahhh i got a welder in the garage simular to to one above and i never realized it could do TIG! all i need are the attachments! SWEET!! im in buisness now! i've been wanting to weld aluminum!
thanks Duane
Those little inverter welders are usually DC only, so TIG welding of aluminum isn't possible, steel/stainless only. For aluminum you'll need an AC power supply and a high frequency unit.
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http://www.millerwelds.com/products/tig/dynasty_200_series/
This one's more money, but still portable and with AC and DC tig output.
Based on this eBay listing I would assume the street price is lower than list price:
click here (http://cgi.ebay.ca/MILLER-907099-01-1-DYNASTY-200-DX-TIG-WELDER-NEW_W0QQitemZ330190376123QQihZ014QQcategoryZ113743QQrdZ1QQssPageNameZWD1VQQcmdZViewItem?_trksid=p1638.m118)
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ahhh i got a welder in the garage simular to to one above and i never realized it could do TIG! all i need are the attachments! SWEET!! im in buisness now! i've been wanting to weld aluminum!
thanks Duane
Those little inverter welders are usually DC only, so TIG welding of aluminum isn't possible, steel/stainless only. For aluminum you'll need an AC power supply and a high frequency unit.
yep your right! Quick TD i just looked at the one i got and i can only DC tig with it!
well atleast i can TIG though!
I have an argon tank a gage w/regulator all i need is the tig wand and hose!
and i can do my stainless exausts!
Zulfigar i gotta ask? are you near the war that going on? if you know where Binladin is at? i'm sure there is a reward for him? not a serious question just curious though?
thanks Duane
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yeah Iraq is like 2 countries eastwards. been there a few times too - when there was no war i.e.
Binladen - when I get my hands on him Im gonna make him remove an mk2 starter without jacking the engine :)
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lol, mk2 humour.
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yeah Iraq is like 2 countries eastwards. been there a few times too - when there was no war i.e.
Binladen - when I get my hands on him Im gonna make him remove an mk2 starter without jacking the engine :)
HA HA you know you could cash him in to the US and have someone change your starter in what ever country you want? plus he might get an RPG stuck in your front end in place of a metric wrench? OUCH!! :lol:
thanks Duane
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i dunno what you guys are talking about i don't see much on seam welding. :lol: i have some scans at home of VW motorsport's rally-prep for mkI chassis, including some on seam welding. i will try to find it for you.
as far as seam welding, people who know tend to say that if you strengthen one area, the forces will just be transferred to the next weakest link... so it tends to be an all or nothing type of deal if you want to do it right.
some people have selectively seam welded their cars though and report good results.
i have done neither so i don't really know... other than the stiffer the chassis the better.
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Not seam welding, but to stiffen a chassis this might work more easily from a DIY standpoint, and take less time. http://www.sportcompactcarweb.com/projectcars/0006scc_project_nissan_300zx_part_5/index.html Go to the last part of the article.
http://www.foamseal.org/auto_aftermarket.htm
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Foamed box sections?
Jaguar did this in the early 70's on the early XJ6's. Pour expanding polyuerethane (or was it cynoacrilate?) foam into the hollow box sections. Probably to absorb vibrations rather than to strengthen. That foam also absorbed damp. Those things rotted faster than carrots. That is probably why no car maker does it now.
If you do want to give a home to damp and salt, try a boatyard as this stuff is used for adding flotation. Sold in two seperate gallon cans, A&B.
Just mix A with B, wait 4 seconds, gets hot and expands, LOTS!
Locally a cuckolded boatwright couldn't find his rival, finds rival's BMW, pours in a couple of gallons through the sunroof. The pictures of the aftermath were genius. :twisted:
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Actually if you read the whole article, they note that this is low expansion, as high expansion can actually distort the framerails. It is also closed cell, so that it wouldn't hold moisture. I have a car that had a similar product all over the bottom of the chassis (no idea why- possibly noise reduction or "undercoating"). When I bought it I was afraid that it would have lots of hidden rust, but because it is closed cell, when I cleared down to the base metal, it looked like the day it rolled off the assembly line. This product is not the same as the home insulation high-expansion foam.
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The 'tex has some good discussions on seam welding. Main thing is to remove the sealer in between the seams or else the welds will suck. Also, don't do a continuous weld. Weld 1", skip 1". It's called stitch welding. Personally, I think reinforcing the frame on a Mk2 can only be a good thing seeing as how much they flex.
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im in the process right now besides custom firewall
(http://img258.imageshack.us/img258/4892/hpim1096tp4.jpg)
my miller 135 is great
so is the plasma cutter
i was told: weekend warrior,get a lincoln(junk)
serious DIY,or pro,get a miller
(http://img134.imageshack.us/img134/4383/hpim02542bg.jpg)