In my current wagon project I am on the gas tank phase of the LT1 conversion. Instead of spending 800-900.00 for an aftermarket fuel injection tank and pump I decided to make use of the factory TA pump and tank.

This requires extensive modification to the pump,pickup, and sender assembly. I am now ready to weld it back together in its new positions but is is all galvanized. What is the best way to remove the coating to weld it up?

I am also using the facory baffle out of the TA tank. I think the best way to mount it will be to glue it to the bottom of the wagon tank. What will hold up to permanent gasoline enviroment?

If you wanted to remove the coating, you could use a red ROLOC disc. But you really don't need to remove it at all. It is simply a zinc coating just like weld through primer. It will smoke, and you certainly don't want to breath the fumes, but it will not hurt weld quality. graemlins/waving.gif

Be darn careful if you are welding on an used
fuel tank, they can explode on you even if they
have not had liquid fuel in them for a long time.
I am no expert but I would fill it with water
and or flood it with C02 or some other inert
gas while welding.

Try body panel adhesive for the baffle,if it will hold a 1/4 panel on then why not a baffle graemlins/waving.gif

Rick

Richard, i will need to do the same thing on my wagon. you can do like martin says, just weld it. por-15 worked wonders in sealling the pinhole sized holes in the weld when i put a sump in my chevelle tank. it is hard to get a gas tight weld.

WHAT ever you do REMOVE the coating on and around the weld zone!! If you dont you can get zinc oxide poision in no time. Grind away the coating with a red disc like what martin said and extend past the zone about 2-3 inches.

Hear me now thank me later... REMOVE the coating. Zinc oxide poisioning isnt something to mess with, it will F*&^ you up. If you get a high enough douse it will KILL you. I spent 2 days in the hospital from it and suffer side affects everyday since and that was 5 years ago :eek: Breathing capacity is shot, coughing and spitting crap up, dizzyness.

Now when I weld on anything whether its just plain steel or galvanize(which I try to refuse to weld now) I wear an approved welding mask under my helmet...period. Also have a small fan that I modified and set it up so it sucks away the weld fumes.

When you weld that tank MAKE sure you have plenty of fresh air moving around, take breaks and breath fresh air from outside. If you start to feel light headed or feel differently in any way stop. Go to the house drink milk like its going out of style and go you should probably go to the hospital. Also the best idea is TELL someone where you are and what you are doing, that way if something does happen they know where and what happened. Iam lucky someone found me pasted out otherwise I would be Dead...Eric

Hey Eric, what exactly did you do to get the zinc fever? I real am curious to the EXACT circumstances of your illness. I know that weld through primer has a lot of zinc and of course "E" coat has a lot of zinc. I weld this stuff all the time. I do wear a small welding respirator under my helmet. But I am wondering about the outside limit. I hate to ask this but for everyone envolved, what did you do to get so exposed?

I know it may be embarrassing because you "should have known better" but that is the point. We ALL "should have known better" at one time or another. I want to know how close we are getting to doing what you did, I have a feeling we get WAY to close for comfort. graemlins/waving.gif

Is this work needed to be done on the pickup assembly, or the tank itself???

NEVER, NEVER, NEVER weld on a used tank...it's way too dangerous, even if it's been tanked/cleaned. A good friend of mine is/was a professional welder and used to weld on tanks until he had one expode on him...never again he said.

This came up on the American Welding Society site and every career welder on there wouldn't touch a weld job on a gas tank with a 10 foot pole. The AWS has strict rules on not welding containers which previously held flamable fluids.

If the tank needs welding, simply spend the extra $1-200 and buy a brand new tank that has never had fuel in it...it's the only option IMO if a tank needs mods...it's your life and those around you were talking about here.

Originally posted by SS70SS:
Be darn careful if you are welding on an used
fuel tank, they can explode on you even if they
have not had liquid fuel in them for a long time.
I am no expert but I would fill it with water
and or flood it with C02 or some other inert
gas while welding. I've seen another trick for this, but must be done outdoors and with only the best of ventilation. Run a hose from the exhaust pipe of an idling car into the gas tank. Exhaust gases are inert, but you have to make sure not to put yourself in danger of carbon monoxide inhallation. An oldtimer at work proved to me that this works. But, in my opinion, there is always an element of risk. Maybe you could spring for a reproduction tank and modify it? I've welded tanks, but you couldn't have shoved a sharp pencil up my :eek: !!!

OK to clear up some of the confusion I am not welding on the old tank. I bought a new repo tank for the wagon. All the modifications are for the pump and pickup and mount. Go to the link and you can get a better idea of what I am doing. Sorry for the confusion.
http://www.chevelles.com/forum/ultimatebb.php?ubb=get_topic;f=31;t=001006

I am still not sure what to use on the baffle to glue it in. Will the panel adhesive live in a permanent gasoline enviroment?

I think you better go to the manufacture of the adhesive and see. I could be willing to bet there is an adhesive that is made for this. You just need to find which one.

Originally posted by Randy Mosier:
</font><blockquote>quote:</font><hr />Originally posted by SS70SS:
Be darn careful if you are welding on an used
fuel tank, they can explode on you even if they
have not had liquid fuel in them for a long time.
I am no expert but I would fill it with water
and or flood it with C02 or some other inert
gas while welding. I've seen another trick for this, but must be done outdoors and with only the best of ventilation. Run a hose from the exhaust pipe of an idling car into the gas tank. Exhaust gases are inert, but you have to make sure not to put yourself in danger of carbon monoxide inhallation. An oldtimer at work proved to me that this works. But, in my opinion, there is always an element of risk. Maybe you could spring for a reproduction tank and modify it? I've welded tanks, but you couldn't have shoved a sharp pencil up my :eek: !!! </font>[/QUOTE]It may work, but Carbon Monoxide is a flammable gas (source-NIOSH pocket guide 1997). It has a flammable range of 12.5%-74%... I am not sure what amount of CO is in exhaust though.

I think I can answer the adhesive question.

My job is advanced engineering applications for automotive structural adhesives. I work on the stuff that is 5-10 years out from production. We are currently developing an adhesive for bonding plastic and metal fuel tanks that will pass LEV and PZEV (zero emissions). It's 97% done.

Currently, there is no commercial adhesive that will hold up to direct gasoline exposure over the life of a vehicle (I'm talking 150,000 miles or 10 years). You can get an epoxy to last for a little time, but this is a temporary fix.


Have the baffle tack welded.

Crankshaft

Crankshaft, you are just the guy who needed to lend some expertise in a discussion we had a while ago. http://www.chevelles.com/forum/ultimatebb.php?ubb=get_topic;f=3;t=007509;p=1

I would really like to hear your input. I am sold on adhesives and the growning use of them in manufacture and repair.

I have a couple of questions right off the bat

1. What kind of tests have you done, or seen that display thier use in structual locations?

2. How about different brands, are there any to stay away from or are there any that stand out as much better?

http://www.rodder.com/ubb/graemlins/rockband.gif

Crankshaft, where were you when we had that topic on gluing panels smile.gif

Also like Martin I think we all could use your first hand knowledge on structural adhesives. I too a have few questions. Bevelling the edge is that the trick or cure to rid the sight line or ghost line that can appear later down the road? Also when doing something like splicing a 80% quarter is there some type of cure time before its subject to any type of sanding, vibration etc that could cause the sightline? How about crash testing done at lower temps?

Hey Martin did you get my email last night on the zinc oxide?...Eric graemlins/beers.gif

Originally posted by sneal46:
</font><blockquote>quote:</font><hr />Originally posted by Randy Mosier:
</font><blockquote>quote:</font><hr />Originally posted by SS70SS:
Be darn careful if you are welding on an used
fuel tank, they can explode on you even if they
have not had liquid fuel in them for a long time.
I am no expert but I would fill it with water
and or flood it with C02 or some other inert
gas while welding. I've seen another trick for this, but must be done outdoors and with only the best of ventilation. Run a hose from the exhaust pipe of an idling car into the gas tank. Exhaust gases are inert, but you have to make sure not to put yourself in danger of carbon monoxide inhallation. An oldtimer at work proved to me that this works. But, in my opinion, there is always an element of risk. Maybe you could spring for a reproduction tank and modify it? I've welded tanks, but you couldn't have shoved a sharp pencil up my :eek: !!! </font>[/QUOTE]It may work, but Carbon Monoxide is a flammable gas (source-NIOSH pocket guide 1997). It has a flammable range of 12.5%-74%... I am not sure what amount of CO is in exhaust though. </font>[/QUOTE]Apparently, it burns off enough oxygen so that combustion cannot occur. I've heard that pipeline welders will flood a hole around a break in a natural gas pipeline with natural gas, cover the top of the hole with a tarp, and with the aid of portable breathing equipment they'll go down into the hole and weld up the pipe. As long as there is not enough oxygen to support combustion, they can do so without setting off the gas. It would take an enormous pair to perform that kind of work. You couldn't shove said pencil up my :eek: if you drove it with a hammer if I were down there doing the welding!!

Found this text in my old ASE books, refers to welding on galvanized metal.

Hopefully the image comes up
http://photos.yahoo.com/bc/sevt_chevelle/vwp?.dir=/My+Photos&.dnm=welding+text2.jpg&.src=ph&.view=t&.hires=t

Srcew it you just have to click on the link I give up :mad:

Anyway this text holds true to MY style of welding. It might not be so true when referring to someone else's way of welding, its just a general rule. But anyway the point is read the text on the lower right corner Where it says CAUTION

In the text it says dont remove the zinc coating for rust preventive reasons but MY health and safty is far more important then someones car not rusting, remove the coating!! graemlins/thumbsup.gif

Check my post reply on Tech 03

MARTINSR and Sevt_chevelle,

Wow! Pro-glue. That's good to see!

I read through that thread MARTINSR posted the link to; very interesting. I think I can help you guys out.

As far as testing goes, I have run multitudes of tensile, shear, peel, and impact tests to determine modulii, elongation, and toughness on adhesives. Based on the application, these adhesives are then tailored to fit the program (application).

One of the new Jaguars has an all-aluminum frame, bonded together with our epoxy. This is Jaguar; imagine the spec testing we had to go through to get that commercialized! :D

I have also bonded a Chrysler prototype vehicle together, then Chrysler crash tested it with no bondline failure. Our direct competitor had catastrophic failure.

I've done the welded coupon vs. the bonded coupon test here to show the OEMS just what adhesives can do, and they are always amazed. We have several 50,000 lb. tensile testing machines at the lab and had bonded a section of 1/8th thick square tube (4in by 6in roughly)inside of another tube, leaving a bondline thickness of 0.010. This had a 4 inch overlap. When we pulled it, it broke the machine.

The thing to note is that this has more to do with overlap than ultimate adhesive strength. One of my areas at work is bondline design; I work with a leading university on this subject. The design of the joint is as critical as the adhesive itself. Think of it as a system approach.

Airplanes have been glued together for over 50 years (the rivets you see on the hulls are what they call "redundant saftey", and are not actually necessary). Helicopter blades are bonded together (each blade is made up of two different pieces and types of materials; joint design also plays a key role here). There has never been one recorded adhesive failure in the aerospace industry.

Right now, every car made in America is bonded with our urethane windshield adhesive. The OEM's have done modeling simulations and real world testing to prove that the windshield is a significant structural part of the car.

When you bevel an edge of an overlap, you are reducing stress concentrators, which happen when a tensile or compressive force is applied to the joint. Curiously, you will see no force in the middle of the joint, just near the edges (this is why you bevel them).

As you guys thought, read-through is caused by differences in CLTE (coefficient of linear thermal expansion)and residual stresses. What you must do is match the adhesive's CLTE to the metal's CLTE (or get them close). Elongation of the adhesive also plays a role. I will run DMA (dynamic mechanical analysis) tests (among others) to determine this over the temperature range. You can also minimize this with the thickness of the adhesive bondline. Thinner bonds with more overlap are much better than thick bonds with small overlap.

Sample prep is big with adhesives. Same as with a paint job; better prep, better outcome. Removing all contaminants on the surface is key to good adhesion. It also plays a big role in corrosion undercutting (migration of corrosion between the adhesive and the substrate).

I would need to know what type of adhesive you use to be able to tell you the way to properly cure it. Urethanes, epoxies, acrylics, cyanoacrylates, etc. are all different, and have their own methods.
For example, the Jaguar frame epoxy is heat cured at over 365°F for 15 minutes. It is also a single component adhesive.

This has become a long post and I don't want to bore you guys, so I'll end here for now. If you find any of this interesting, I'd be happy to keep going.

Crankshaft

Crankshaft, I have to say that was very interesting, keep it coming graemlins/thumbsup.gif

As for my adhesive of choice I use 3M's 8115. Good bad or indifferent?? Thanks...Eric

Crankshaft, bored Hell, that is some SUPER GREAT stuff!! I use a Windser product I am almost positive it is only marketed by them and is manufactured by someone else. We have at the shop Windser, WURTH, SEM and Fusor but I belive we will be sticking with Windser. I will get the part numbers and let you know.

One the subject of the thickness of the adhesive, Am I correct in that all the different products along the same "technology" like all epoxies, all urethanes, and so on would have similar traits in how thick they should be?

Let me start with that one question, I will have many more after I start thinking about it. smile.gif graemlins/beers.gif GREAT STUFF, thank you!

MY RESTORATION SHOP SAYS IT IS DANGEROUS TO WELD GALVANIZED MATERIAL SINCE IT IS POISONOUS!!!!!
MY RESTORATION SHOP SAYS IT IS DANGEROUS TO WELD GALVANIZED MATERIAL SINCE IT IS POISONOUS!!!!!
MY RESTORATION SHOP SAYS IT IS DANGEROUS TO WELD GALVANIZED MATERIAL SINCE IT IS POISONOUS!!!!!
MY RESTORATION SHOP SAYS IT IS DANGEROUS TO WELD GALVANIZED MATERIAL SINCE IT IS POISONOUS!!!!!

Hey guys,

I will do some research at work to see what all information we have on 3M 8115 and all of those names that MATRINSR named off (I know we have tested Fusor before). I can even test out 3M 8115; what specific information would you like on it?

MARTINSR,

Yes, you are correct. Adhesive families will have similar thickness.

Now, let me ask a few quick questions...

Are you guys mostly focused on metal bonding with room temperature cures? Or do you also do plastics (which has been my particular focus the last few years)?

We also have a whole sealers group that does nothing but hemflange, roofditch, etc. for the OEMS. I can tap them for info as well.

Crankshaft