Hey guys. As title says, I'm getting a welder. Yes I've already read up on welding do's and dont's and I've welded before, just not much. But don't worry, I'll be practicing ALOT. I'm getting a Lincoln...either a sp135t, or a weld-pak 3200HD. Depends on price and availability. I'll be using shielding gas at some point, but at first I may just use flux core until I get the cash to get a cylinder. Anyway....I'm really looking forward to having this and thinking of all the things I can do with it. Soooo i need some advice with all these ideas I keep having.

First of all, I have the Fender Braces bolted on, but they make somee creaking noises. I wanna strengthen the upper mounting point and weld them on, or at least just weld themon. I was planning on doing so with the chasis loaded, of course, and I'd only weld the top mounting point so that you could still unbolt it from the door if it needed to be removed. Anything wrong with this plan?

Next, the SFCs. I saw a thread about seam welding the SFCs on. Since I won't be paying for labor, I thought this might be a worthwhile investment. IIRC it was VQuicks car, and Broaner did the welding. VQuick said he didn't see any adverse affects of doing this...I'm just wonderin if there's a good reason I shouldn't do it. And also, as with seam welding the rest of the car, should I space out my welds and alternate sides?

Ok, now regular seam welding...bad idea? I'm really wanting to do this, or at least to some parts that I think could benefit.... like shock towers (front and rear) as well as the trunk area right behind the seat and all around the shock towers, etc. Also, what If I just wanted to do the trunk area for now...and then next summer pull the engine for some cams and seam weld the engine bay then? Or should I really do both front and rear at the same time?

Lastly, what about bracing the rear strut towers. Everything in the area right behind the seat just looks really stamped and thin and flexible. What if I made a rstb like this:http://i285.photobucket.com/albums/l...IMAG0257-1.jpg
Yeah, I know it would get in the way of the hole...but i don't care. If it actually made a tangible difference, I'll deal with the lack of hole. There are other pics of my trunk in that album so you can see what I mean by everything looking flimsy. If that idea for a brace doesn't look too great...what design *would* work best (in theory) for a rstb? I really want to tighten up the *** end of the car in an effort to reduce understeer, but I don't want an RSB....rather focus on chasis stiffening in the rear.

Thanks for the help guys, and feel free to share your ideas!
Josh

 

41 reads and nothing? Apparently nobody wants to talk seam welding and chasis bracing

 

Are you planning on racing this car at all? I'm a little fuzzy on the details, but I believe some sanctioning bodies/classes limit the amount of connections you can have between SFC's and the body of the car.

I'm not an expert, but I do know sheet metal is tricky to weld. You will definitely need to limit how much welding you do at a time in a given area. If you put too much heat into such thin metal, you'll cause it to buckle and warp. I think they recommend you do about an inch at a time in each area, then move several feet away to do the next weld. Also, prepping the area (paint/undercoating removal) is probably going to be a little tricky in areas and could result in small fires and some nasty fumes. Before you do any welding, make sure you disconnect the battery AND the ECM so you don't fry anything. Last, welding old, thin metal is not the easiest to do well, so practice as much as you can before you attempt to seam weld your entire car.

I have a RSB on my car and it makes a world of difference in the corners without really affecting the ride. Easily the best modification I've made to improve handling. I don't think chassis stiffening alone can make up for all the weight up front...

Have you looked into chassis foaming at all? This would need to be done after any kind of seem welding, but it's a way to stiffen your chassis considerably with very little weight penalty. It has the added bonus of dampening sounds as well. Check it out....

Sounds like you have alot of ambition...good luck!

 

A quick rundown..

1. neither of those welders really have the juice to do much more than 1/8" plate. they'll be fine for seam welding the chassis, but are borderline for installing SFCs.

1a. Don't even think about touching anything but big ugly parts of the car until you get a bottle of C25 and solid core welding wire. that flux core crap makes for UUUUUGLY welds. MIG welding is much easier and cleaner and nicer looking.

2. Why bother seam welding a MAXIMA? It's not a competent race car, never will be. call it rude, mean, harsh, pessimistic, whatever.... I call it like it is. don't waste your time turning a Maxima into a "race car". Been there, done that. my stock 240SX handled better than my extremely modded Maxima.

2a. Seam welding a car that's had seam sealer glued into every seam on the front end is going to be a MAJOR mess, and usually results in more losses than gains because you wind up burning holes in the sheet metal while you're trying to burn through the goo that you can't ever get out of the seam between the sheet metal parts.

3. RSB does completely different things to chassis dynamics than stiffening the chassis. proper sway bars are essential with any chassis and suspension setup, even more so when you start stiffening the suspension.

4. seam welding the SFCs really won't net you anything but a mess. weld them on in about 5-6 places each side (regular installation is about 3 or 4 places), and call it good. very small gains, if any, to seam weld down the SFCs. you'll add a lot of weight in materials and catch half the car on fire.


don't take my comments as me being a ****... I've just done most all of it myself (in fact I own the same SP135t welder...) and wasn't happy with the outcome. If you want a track car, buy a proper RWD chassis and keep the Max a clean looking "sport sedan". Hopefully my comments will spare you from spending the time and money on a car I was never happy with in the end.

I've since started de-modding mine back to DD status. I've only lost a couple sec per lap at the road course, but the car is MUUUUCH more comfortable to drive and doesn't eat tires for breakfast like it used to when I was tracking it.

 

I don't have much time, so I'll reply to the rest later...but for now, what other options for welders do I have?

The problem is that I can't get a 230v. All three places I would use the welder only have 115v outlets....can I get anything better than the sp135t without stepping up to a 230v? Is the 140t any better, or just the newer model?

And, you're saying no more than 1/8 with shielding gas, right? I *could* weld a little thicker if using flux core, right? I just can't afford to spend 700-800 on a welder and then another 125 for a cylinder and getting it filled. Don't get me wrong, I don't want to skimp on the welder...but I DO have a budget.

And do I really need something better? I mean with practice I could take care of the SFCs, right? And I doubt I'll be welding anything thicker than that...

 

The SP135 is fine for 1/8" metal, but for an 'amateur' welder, I wouldn't tyr anything that deals with the frame.

And yes, I completely understand being on a budget.... buy why buy the wrong tool that will do more damage than good just because you didn't want to wait and spend the extra 15%?

FYI, the SP135 is in the $550 range around here. After welder, bottle, welding mask, gloves, some expendables (more wire, tips for gun, nozzle gel, etc) I was around $800 or so for the entire setup.

My recommendation is to wait and do anything that needs to look nice until after you have the proper setup. You'll also have to completely re-learn to weld when you switch between flux core and solid wire. it's a completely different technique. I used it a bit at first just sticking some pieces of scrap metal together, and finally gave up and bought the gas bottle.. WORLD of difference!! It's worth it to wait.

Patience, young grasshoppah.

 

yea, ive been welding with my sp135 on nearly a daily basis for the last 6 years, and i agree. learning to weld on the seems of a car would be horrible. The sp135 can do thicker than 1/8 but you have to be patient, lots of heat and move slow to let it penetrate. And whatever you do.. do it with gas.

 

Not necessarily a race car, but no chassis stiffening is too much.

He was talking about a RSTB, not a RSB.

I'm not sure I get how anything will increase over the 4 "tab" connections per the regular SFC installation.

 

I don't think I said it was a race car...I suppose maybe the extreme I'm taking this to might make you think that was my intent, but it's simply my DD. I don't autox or anything so this isn't for competition, I just enjoy driving my car.

And I've thought about getting a car better suited to being a "race car" but it just wouldn't work for me. I have to be FWD for snow reasons as I can't afford a second car. And I just don't know if I could get rid of the Max...I like being different. And while the car will never be the best at anything...it'll still turn a few heads.
You're right, it's not and never will be a race car, but I like the car and I'm keeping it till it dies or until I die...so I just want to make the best of it and see what I can do with this "family car."

didn't think of that...so I guess it's a good thing I asked. Sounds like a pain....but would it be that bad If I only seam welded a couple areas? I'm not talking about seam welding the whole damn car...just the front and rear strut towers and surrounding areas. maybe a couple more places.

I know, it probably won't make a big difference...but at some point I'll be looking for more ways to stiffen the chassis...and well...this would be free. Every little bit counts right?

This I know. I was wanting to avoid getting a RSB because:
1. its added unsprung weight
2. I hear it makes the rear end less compliant (skips over bumps and stuff) on crappy roads when used with lowering springs...and the GCs already have higher rates than other springs.
3. it's one more thing I have to buy.

so are you saying that since the GCs have such a high rate, a RSB might be more necessary for me than someone with eibachs or h-techs?

ok deal. that'll be cheaper and easier anyway.


Don't worry, I understand. I really appreciate the honesty. Its good to get some info I know I can count on, even if it is brutally honest.

LIke I said, I'm pretty much stuck with the Max for a loooong time to come. So I might as well enjoy it and see what she can do. I already know she can do more than *most* people are aware of....but obviously, she'll never be a race car.

 

That's what I was thinking.

I think Matt was referring to me NOT wanting an RSB...but you're right, I'm also wondering about making a RSTB. I have that pic up there of my idea...but I really have no idea what would be strong/beneficial or not. That's why I was hoping Matt would take a look and tell us his thoughts.

Matt, bad design? What about a 3 point rstb that tied into the floor? I've seen those made for some cars. Would there be a better design for bracing the rear of the car than the typical aluminum bar between the strut towers?

 

sooo after lots of pracitce? like weeks of practicing every day? how would you decide when I'm ready? I guess I'll just have to show some pics of my work, when the time comes, and let you decide

are you referring to cheaping out on the gas and using flux core?

I found the sp135 online with a cart (holds up to 80cu.ft. cylinder)for 475 shipped. Then I was going to get a miller pro-hobby helmet for 140. But how big of a cylinder do I need? would a 40 be alrihgt, or should I get an 80?

That's my plan now. No welding until I have gas. Thanks for your words of wisdom.

yes sir!




Trust me, there will be MUCH practice before I touch my car with a welder...I don't intend on "learning to weld" on important structual pieces of my car .

but thanks for the advice, that's what I was wondering!

 

1. As someone that was in your shoes once and didn't have a clue about welding, I suggest you at least take an adult education program at a local college or high school. They'll teach you all the basics and some advanced stuff, enough to get you in the right direction and give you lots of practice. I highly suggest it. If you love your car as much as you say you do, you owe it to your car to do this right the first time as welding it wrong is irreversible.

2. Speaking of irreversible, you definitely need the practice so you don't do two of the worst things you could do to a car while welding: burn a hole through the metal or worst yet warp the metal. I think Matt already talked about that here a little: http://forums.maxima.org/advanced-su...m-welding.html , but there's a reason why most race shops that will weld a factory car use stitch welding instead of seam welding. Once you start practicing welding, do a long, continuous seam weld on a piece of spare metal and let it cool; you should be able to see how, if overheated, it now bows in the middle. That's exactly what you DON'T want to happen to your chassis.

3. Get a GOOD welder, not a decent one. Sure, it'll cost more, but you can do more with it and you'll thank yourself later. Gas is your friend.

4. If you're really serious about doing the car, do it properly. Take it all apart, and I mean ALL of it, removing EVERYTHING, and put it on a rotisserie. I'm going to sound elitist here, but if you're not willing to do that, you're more likely to rush through things and screw something up, and you'd be better off sticking with bolt-on suspension parts. Sounds bad but really, a project like welding a car is long and drawn out. The few people I've talked to that did their entire cars took somewhere between 40-60 hours to do it, and I'm not sure that included the removal of all parts and bits. See what I mean? This isn't an "after work, on the weekends" project you can do in a month. Like I said, not trying to sound elitist, just saying it like it is.


Off Topic:
I drive my 240 in the snow all the time and I've never had a problem with it. Snow, ice, sleet, hard rain.

Lot and Matt's right, it's sad when you dedicate so much to a car to make it handle better, then find out your stock 240 handles better than the car with 100 handling mods on it. Oh well...

 

Yes, I'm new to welding...but that doesn't mean I don't have a clue. Don't get me wrong, I have MUCH to learn...but I have at least welded before (with both flux core and shielding gas). After having a custom catback made once, they did a crappy job on the welding....so I had to patch it up. It wasn't pretty, but it was air tight. IMO, lots of practice will be enough. I wouldn't be jumping into this if I "didn't have a clue," and/or didn't plan on practicing my butt off.

Not only that, but with 40-45 hours of work each weak and 15 credit hours at the local college, I haven't got the time for a welding class.

IF I ever do any seam welding...it will probably be the last thing I do. I would think I'll have *enough* experience within a few months, no?

(sorry if I sound like an a$$, but I do appreciate your input!)

No worries, I'm fully aware that I could easily fawk up my car.
From my above post:As I posted above...I'm getting about the best I can without stepping up to a 230v welder (correct me if I'm wrong). Any place that I'd be potentially using the welder only has a 115v....so that just doesn't work. I understand your advice, and trust me, I'm realizing it would be worth it to fork out more cash for a better one...but I wouldn't be able to use the thing anywhere.

First of all just no, lol. And secondly, there's no way I'll ever strip it down and seam weld the whole thing. I was merely wondering about doing this in certain areas of the car. I've been reading about this along time before I posted this thread. I've seen a sh!tload of people warning about the dangers of seam welding...so that I'm aware of. I'm just wondering if it would be "beneficial" to do some areas of the car (assuming it's done properly) seeing as "every little bit counts."

and bolt on chassis bracing...you mean like the rstb comments in my first post that nobody has responded to?
That's actually a bigger focus and more realistic than the seam welding idea. I've been wanting to make an rstb, possibly make or modify a LTB to fit with the headers (davevq has done it), and I'm curious about other possible benfits of traction bars.

I really want an LTB, but, I have teh headers. Before I begina quest to make one fit...would traction bars aid in any similar ways that a LTB might? I know the LTB ties the control arms together, and traction bars dont, but traction bars DO limit fore and aft movement of the control arms. Could they be a *partial* replacement for an LTB, or should I set out fot the real thing?


yeah I know people that drive RWD vehicles in the snow/ice etc...but it makes a huge difference where you live. I'm surrounded by nothing but curvy two lane roads with huge hills. Some of these roads make 4wd vehicles **** their pants in the wrong conditions. Not to mention my minimum trip is about 25 minutes away. The longer I drive in those conditions, the greater my chances are of getting pwned. It's hard enough with the max sometimes.

Bottom line, there's no 240 in the future. I'll have the max a while, and I wanna make it fun to drive while I have it. mmk?

end OT

 

I do drag race rarely but no autox or anything. Just enjoyable daily driving. I'll definitely look into class regulations, etc. before the install of any permanent extra bracing...but as of now, I don't plan on any racing.
That goes along with alot of what I've been reading. Seam welding will probably be last on my list, if at all...but I'll make sure it gets done right if I do.

Thanks for the input, I may be re-considering the whole RSB idea.

I was afraid of that being the case...

Yeah, actually I have...a little. I need to look into some of the higher density foams and take a closer look at the car. Something Nate (MorpheusZero) pointed out to me was the fact that you have to watch out for wires when chassis foaming or they'll be stuck in there for life. Its on the list of possibilities, just need to do more research..

Thanks dude

 

bummmmp. If you think I should not get the ap135 for ANY REASON, speak now, or forever hold yer peace.

 

No problem here man, you don't sound like an ***, though I'm sure I do, but that's just me so don't take it personal .

I still stand by my statement that if you're going to do any welding you might as well tear it apart and do the whole thing, why do half a job? But since you're adamant that it's not something you can or will do now, then it's not going to hurt to do what you can because some welding is still better than seam glue and tack welds.


Kind of, yes, that's what I meant. Arm braces, the fender braces you have, undercarriage bracing (do you have that?), front/rear strut tower bars, etc. I didn't see a suspension mod list from you, but it seems like jumping ahead to go and start on welding the chassis now. Who knows, you might be satisfied with just the basics?

Not only that, but the previous statement about how you don't auto-x or road race the car and don't intend to, well, it makes welding seem like overkill for a car that's just going to be daily driven (like a Corvette Z06 that's only taken out on sunny weekend drives to the golf course; kind of a waste). Ever think of using chassis foam instead? It'd be easier, cheaper and still harden up the chassis considerably.


The RSTB design looks good, but I'm no Maxima expert so I couldn't tell you if that's a good location for holes/etc or a good shape for the rear design, but once again, any rigidity adding is better than none.

 

Adding a 220 circuit really isn't that difficult. I'm guessing 30A would be enough for the 180-ish 220 kits.

A RSTB is not of particularly big benefit on any car that has any sort of beam axle. Rear wheel camber is defined by the stiffness of the beam axle; whether the chassis side pivot points and spring/shock/strut pickup points are moving around is immaterial for this aspect. It's not like the case with IRS cars where any pivot point movement goes directly into [adverse] camber change.

There might be small gains from the added local stiffness, but if this is only confined to the vertical-transverse plane through the strut tower tops the operative word here is "small". Chassis torsional stiffness is a 3-D problem, the aforementioned plane is only 2-D, and a point-to-point STB is only 1-D.

Additional attachment points beyond the obvious two and specific connection details help, though merely attaching additional bracing tubes to flat areas of sheetmetal that isn't backed up by anything won't add much. There's a reason that roll cage designs that weld up to unibody constructions attach the tubes at places where two or more planes of unibody come together. An "X" bracing arrangement that also connects where the wheelwells meet the floor would probably give you as much help as any single plane bracing could. But even if that's probably the best 2-D "solution", it's still only a 2-D answer to a 3-D problem.

And if you add a RSB, there is arguably LESS need to add a RSTB, since the RSB load path does not involve the strut towers (takes load OFF the strut towers while cornering, actually).


BTW, the worst thing about dealing with the mess that sealer can make is not the mess (assuming that you can keep up with putting all the little fires out). It's that weld contamination becomes all but unavoidable.

There are worse things than welding with fluxcore. Welding where you are subject to enough of a breeze to blow the shielding gas away from the weld comes to mind. If you have no option but to weld outdoors, you may not have much option on this point, though I have heard of people using a little gas along with the fluxcore. I've managed to successfully stitch weld (more like lots of little tackwelds, actually) 22-gauge patch panels to lower quarter panels and sills using fluxcore, so it can be done even though you're in for some extra work after the welds cool.


Norm

 

Interesting thread. I'm currently sanding the engine bay in order to paint the biatch soon. One thing that took my attention while sanding and removing the putty/silicon in the seam, is the fact that the entire front of the car is pretty much spot welded. I'm pretty sure that this cause the front end to flex much more than if it would have been welded properly. Removing the putty/silicon in the seam is not that difficult it just require anyone to take the time and do it properly ( it took me 90 minutes to do half of the engine bay ), to make sure there is nothing left I'm sandblasting the seam with Aluminum oxyde, it make a very good job.

If done properly this will ensure there is no contaminent left before I start soldering some of the seam. Welding the seam with a mig can be a PITA, so what I've decided is to use an acety/oxy torch and use either bronze or silver to weld the seam, it is going to be much easier and will do a much nice jobs, but also the bronze/silver is much easier to sand down if you have too. You just need to have a bucket of water near by or keep a water hose close to where you weld. I'm not going to weld on the firewall, since all the car interior is intact and it is likely that a fire would spread quickly.

 

You know that all that 'putty and silicone' is not just to seal up the seams right? Nissan used that stuff for a structural bond rather than 'waste' time and money on quality welding. Be very careful about what you remove, or you might end up adversely affecting the structural integrity of your car.

Everyone should make sure that there welder, along with there own skills, are up to snuff before they attempt to weld on the thin sheet metal that Nissan provided. Not easy stuff.

I won't even get into how this might affect your crumple zones.

 

Of greater concern is whether or not any of the metal being seam welded or silver-soldered up is a high strength alloy of some sort. The strength properties of most of those steels are adversely affected by hot work even though the stiffness is not.

Edit - this information might be available from a dealership body shop, as they would have to know.


Norm

 

One thing I forgot to say is, in many area where the putty was removed there was a rust underneath and that's not a good thing. From what I have experienced the putty is only there to avoid water getting in the seam. I have a serious doubt that is has anything to do with structural integrity, it may help a bit but it's like saying using duck tape on our car will make them stronger. lol

I will be welding only few of the seam, and will put high quality automotive silicon after it is done. It's not the first time I'm doing this and trust me the car is going to be stronger up to a certain extend after this is done. I already identified few weak link on the front of the car, where there should have been a weld but let me guess the robot cannot access those hard to reach spot, nothing that a human arm cant do.

 

I'm pretty much done with the putty removal, this was not a fun job but I'm happy that I did it. I found a good amount of rust underneath the putty into many seam. I'm finishing the sandblasting today and no regret because of the money I'm investing in that car, the primer / paint / clear cost me 1900$ so painting on rust is never a good things and I want to make an absolutely perfect paint job so preparation is the key. Finally I have decided to re-fill the seam with a very good quality automotive silicon as someone mention welding the seam would have lead the car to catch in fire unless we would have totally undress the car but there is no need for this.

 

If you weld it properly, you *can* weld those seams. you just have to use small wire and low heat to keep from burning through the sheet metal. then only do about 1/2" at a time and skip around so you don't put too much heat in one area and warp the chassis.

The biggest issue is getting all the sealer out of the seam before you weld. nothing can fix a bad weld once it's full of crapola from seam sealer that iddn't get removed.

Also.. Use a good quality seam sealer that's made for the purpose. That stuff actually makes a structural bond and will flow into the seams better than silicone compounds will. much stronger stuff helps all the way around in the long run.

Look for a body supply shop to buy the proper goop.

 

I had the same concerns for years, but after putting the Progress RSB on my car I'm pissed I didn't do it years ago. I haven't noticed any instability or harshness in the rear. Actually, after replacing Ben's rear strut mounts with the stock ones my car rides better in the rear than before After the RSB, the car is just so much more neutral and easy to handle in the turns. No snap oversteer, no jumpiness. Get one