Bob -I have read through your blog. Thanks for documenting things so clearly. I wish I had the time to publicly document my work like that. All I have for now is thousands of pictures and greasy handwritten journal entries.

I took took joey dale up on his offer (as bob suggested). He is sending me the area thats rusted out cut out of a rust free florida car. After rethinking, that is definitely the way to go. It means my work will be fitting it into the car, not bending sheet metal into place like you did.

I got my welding setup complete. I actually ended up getting a Hobart Handler 140, it came with free shipping and a cart for $479 from Northern Tools.

Bob - what settings do you use on the Hobart for welding the MB steel?

An aside: For those looking in the future for which MIG/Flux core setup to buy, the Hobart machine is made by Miller and seems to get universally good reviews. The Lincoln Electric Pro-Mig series is made specifically for Lowes (which made me nervous about obtaining parts way down the road), and was slightly more expensive at $529+ tax. My research concluded the two units were really the same, and I could get the Hobart serviced at my local shop if needed. I got the argon tank and safety gear from my local welding shop. A respectable MIG setup after all the machine, gas, safety gear, wire, and other tools, cost me about $1000, but Ill have it forever and really I just wanted an excuse to get one.

Ill be back with pics and questions when all the components get here and I get get a good look at it all.

Im excited to do this right, even though its turning out to be a lot more than I bargained for.

dd

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'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

Good luck Dan. Congratulations on the new tool.

So what are you going to get to use as your winter beater now.

__________________
Chad
2006 Nissan Pathfinder LE
1998 Acura 3.0 CL
OBK#44
"Pleasure in the job puts perfection in the work." - Aristotle (384-322 B.C.)

SOLD
1985 300TD - Red Dragon
1986 300SDL - Coda
1991 - 300TE
1995 - E320
1985 300CD - Gladys

Maybe with any luck I can keep my 'no salt' car on the road until I finish this. No salt on the roads here yet. But if I get stuck Ill use my sister's 2001 Corolla that is dormant while she is at college (MAJOR downgrade in all respects from a W123). So no worries.

Trust me, once fixed, this car still qualifies for winter beater status :-)

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'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

Did your panel arrive in good shape?

__________________
1988 Toyota Camry Wagon......CRUSHED
1988 Porsche 944.......SOLD
1984 300SD.....SOLD
1995 Honda Civic DX... Totaled 11/13/08
1991 Madza Miata 193K and counting.....Mercedes t3 Turbocharger in the works 10 pounds per RWHP FTW

Joey - Yes it did, thank you! It's great - I now have a piece I can weld in. I am jealous that a car that has zero rust could be in a junkyard FL. Unless it was an accident car, its still driving around somehow up here. I still do need a midnight blue front fender...

The only question now is how exactly to stitch it in, and where to cut. I will need to take some pictures of the piece alongside the car to get opinions. I could cut very high up the pillar in front of the door , but I dont know if that is a good idea.

This is the epitome of 'measure twice, cut once'.

dd

__________________
-------------------------------
'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

That piece is really off of half a car. Its easier to trim the new section than it is to trim the car. I would start by removing all of the rust, if its rustly, keep cutting. Then trim the new piece so that it is exactly the same size and shape as the hole. Then the fun starts. It would be a good idea to get some weld through primer, and use it on both the car and the patch. Make small (10mm) long welds at a time, if you weld to much in one area at a time, the heat will warp the car and panel, and it will no longer fit. Take your time and go slow, and it will all work out.

__________________
1988 Toyota Camry Wagon......CRUSHED
1988 Porsche 944.......SOLD
1984 300SD.....SOLD
1995 Honda Civic DX... Totaled 11/13/08
1991 Madza Miata 193K and counting.....Mercedes t3 Turbocharger in the works 10 pounds per RWHP FTW

Okay, here are some pics. I dont really know where to cut and how much to replace. How should I deal with the rusty jack point - cut the whole thing out?

First a couple shots of the cleaned up rust:





Now some side by sides of the piece against the infected area:





Rear View


Top View


Any ideas on where to cut and how much? I feel like cutting into the vertical pillar would be a poor idea. My main question is how to deal with the jack point itself - the jack point is okay, the stuff around it is rusted.

dd

joey, thanks again for the piece. now that I see the heft and thickness of the metal, I cant imagine doing this with fiberglass or even 16 gauge.

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'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

I would cut out the jack point. The patch that I sent you has the whole thing. Also, I would try to use the patch as one piece, not a little here and there. If you feel up to it you should cut high up on the car, if you cut to low the jack point will be a major pain in the butt to weld in. OK, its past my bed time, so I am going to stop rambling now.

__________________
1988 Toyota Camry Wagon......CRUSHED
1988 Porsche 944.......SOLD
1984 300SD.....SOLD
1995 Honda Civic DX... Totaled 11/13/08
1991 Madza Miata 193K and counting.....Mercedes t3 Turbocharger in the works 10 pounds per RWHP FTW

i'll respond to you tonight on where i'd cut with colored lines. i 'm at work right now

thanks bob - I look forward to it!

__________________
-------------------------------
'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

dd,

ok, lemme write first before i send modified pics. based on my experience and what joey advised, cut out as much rust as possible. the general rule of thumb seesm to be 1" past the edge of the rust. however, here is where I disagree with joey. joey mentioned to cut to shape, but I found better success with straight lines and the least # of lines as possible. the more lines and angles you cut, the less likely you are going to match them all perfectly once you start welding. furthermore, if you weld, the metal will ***contract*** so if you don't put a spot weld on one side and then move to another, the gap on the other side will get incrementally larger.

A-pillar advice: the rust is creeping up underneath the overlapped section. i saw it one too many times on my car and i know for 110% sure that is happening to yours. what you need to do is to (contrary to the rule of thumb above) is to cut away little slivers of the overlapped part until you dont see rust. guarantee waht you see underneath is rusted metal. but the good thing (at least from my experience and my car) is that mercedes puts that yellow anti-rust stuff underneath overlapping sections, presumably to stifle potential rust growth. so if you have an air die cutter or a dremel, cut away. there might be enough metal for you to then weld onto the lower panel if its not too rusted. and remember: always grind down to bare metal. this is where a dremel comes in handy b/c its a more precise tool. weld on a little rust, you will get horrible results. you will know by the sound and by the feel when you are welding on dirty metal vs clean.

jackpoint: its gone. dont even think about salvaging it. count your blessings that joey did such a good job cutting that nice piece for you. its the same feeling i get when my local sushi chef pulls out that big ass piece of fatty tuna from the back for me and the wife you may need to weld in a piece of metal in the area that extends inward...just eyeballing the pics you have.

weld thru primer: mixed feelings on that stuff. i didnt find it really good. but i always tried to use it on the interior side.

tools: do you have a grinder w/ cutting, grinding and flap discs? if no, go buy yourself a $60 dewalt from lowes and a bunch of cutting discs. a grinding disc goes a long way. 24 grit is good for sanding down your donor piece. but get a dremel w/ reinforced fiberglass discs if you dont ahve a compressor and an air tool cutter to do precision cuts

safety: WEAR EYE PROTECTION. wear hearing protection, even when welding. it'll make everything so much more tolerable. also, when you weld, galvanized steel fumes are not good for you. so what i did was i set a box fan a few feet away at speed setting 1. just enough to blow away fumes but not affect the gas coming out of the welder tip. practice and you'll discover what i'm talking about

i gotta do a little work on my car, so i'll post pics later and write a little more too.

dd: this is salvagable. dont fret, you'll do fine.

Attached Thumbnails

     

thanks bob - interested to see your drawings. i cant tell how much of the A pillar you are suggesting to cut into and where. it seems if I want to replace the jack point i have to cut high.

i have a dewalt angle grinder with cutting discs, a dremel with lots of 1.5" cut off wheels and assorted attachments, a full mig setup and a 10lb spool of mig wire, clamps, brushes etc......

Im just concentrating on the sense of accomplishment ill feel :-) seriously though, im having a lot of fun. too bad its now really cold out in the garage.

dd

__________________
-------------------------------
'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

bob,

Sorry - didnt see your drawings until now. they look great! I like that methodology.

o you are saying leave the jack point itself along, right? Just cut the sheet metal around it and re-weld in around it? I like that idea - leaving the structural stuff alone wherever possible.

I will take pics as I go through the whole thing. The A pillar is not bad, by the way. I wont have to cut much.

Thank you!
dd

__________________
-------------------------------
'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

Spent the weekend going through and fitting in the piece I go from Joey. I had to split it into two pieces, I just couldn't get it to fit other wise.

Of course this post would be much more meaningful with pics, but I forgot my camera at home. Ill post later.

So here's my question for now:

So now with the pieces fit up, I do have some gaps between the two pieces I need to fill butt welding. Some up to 1/4". In some spots I can stitch in slivers of 16 gauge, but on most its pretty close. What's the best technique for gap filling? I have seen references to putting a backing piece of non-steel behind the gap to extend the weld pool (i.e. copper), but I dont know if this is valid here.

I practiced MIG welding with my new Hobart 140 last night for the first time. Cool! I can lay weld beads easily, and even do butt welds too. But I am having a hard time gap filling, hence my above question.

Pics later tonight..
dd

__________________
-------------------------------
'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

Turn the heat down, increase the speed and use .030" or smaller wire. Are you using gas or fluxcore? If you are using gas then dial the gas down as low as you can go.

Filling is a breeze once you get the settings right. You can fill a panel easy enough using a copper backing plate but I doubt you have access to the areas you are filling.

Small beads around the edges, let cool and then return. Get the edges close, build a "bridge" and fill the gap in a circular bead.

If you are using fluxcore then be sure to hit the bead after each pass with a wire brush to get a good solid weld.