3m Panel Bond instead of welding?

[michigan4x4]

I widened the wheel wells of my M101a2 trailer and welded everything back together to give me over 48" between the wheel wells. To be honest, my welding is not the best and I had problems with burn through a few times.. Part of the reason was my Mig wasn't set properly and the other reason was that I was working outside and I think the shielding gas was blowing around a bit. Wasn't fun and had to spend a lot of time grinding big messy welds.

To make a long story short, I did so much grinding that I seemed to have thinned the metal on the wheel wells along the welded seam. Now, in order to restore some rigidity, from the underside, my plan is to fab up some 5 inch wide sheet metal patch panels and use 3m Panel bonding adhesive 8116 to set them in place along the underside of the welded seam. Anyone have any experience using this stuff. I know I should just pull the welder back out and weld them in but I seem to do more bad than good with the welder.

Suggestions, opinions etc..

Thanks
Jeff

 

[gimpyrobb]

I'd just run a bead of seal sealer where the metal meets and call it a day.

 

[hcso1988]

I can't say much about the panel bonding adhesive personally. But as far as your welding troubles, I can give you a few pointers there (work for a city municipality in the maintenance department and we do a lot of welding on various items). From the sounds of it you would be best to turn your heat (voltage) down on your welder. Mig's are great as long as you set them right. It's best to set it a little lower than what you need, and move a little slower to get the metal to bond, than to have it cranked up and blast holes in your project. As as far as your shielding gas goes, that is just there to protect the weld from the atmosphere and instant rusting. If all your shielding gas was blowing away (or had run out) you would see instant little pours forming in your welds and they would look God awful and splatter like crazy. Hope that helps a little, even though I didn't answer your direct questions.

If it were me I would set the welder back up and give it a go again. Practice makes perfect my friend!

Blaine

 

[0311DAD]

i do collision work for a living, and use panel bond quite often. Panel bond is only good for cosmetic panels. it should never be used for structural repairs. hth

 

[zout]

Good possibility the 3M bonder is going to eventually break and separate away.

Like a member said when you close to sealing the seam use the seam sealer.

Mig - no doubt with it windy it was making your gas non-existant and setting really sound like they were way off for body metal.

Get the setting correct and you will have little grinding to do it you set it all up properly (this includes your patch piece). Dig the mig back out.

Pics to help you would be nice with you are describing what your working with - it might just be an ole rusted out POS you have and we are all thinking something different trying to assist you.

 

[flyxpl]

In a collision ,every panel is some kind of stuctural piece . I would not be scared to use it on some fender wells , it is not like you are riding in the trailer . 3m panel bonding adhesive is some good stuff . I would not have welded any of it . If wheel wells are glued in , you would have no bare metal = no rust . In some applications like a bed side , it would be welded in the front and rear , everywhere else 3M 3115 panel adhesive . Even without the wheel wells that trailer is a tank compared to most cars .

 

[swbradley1]

If you have some more sheet metal to practice on hcso1988 is correct, practice, practice, practice.

 

[michigan4x4]

Thanks for the input guys. I know I should pull the welder back out but the monotony of welding/grinding is getting to me. This is really my first major welding project and I just don't want to burn more holes in the trailer nor do I want to have to grind more than normal making other areas thin. The trailer is not rusty at it. In fact, it is in very good shape. Because it is in such good shape, I am starting to rethink my project. Part of me thinks i should have just left the thing alone, shot a coat of paint on it and called it a day. Now I feel like I have a patched up, burnt through, mess on my hands.

I read somewhere that a normal weld has a tensile strength of 1500 psi where the 3m panel bond has a tensile strength of 3,000-4,000 psi. So the Adhesive is plenty strong for the project I am working on Heck, Mercedes, BMW etc has some cars now that are almost completely glued together using this type of adhesive.

Thanks again..
Jeff

 

[zout]

If I recall correctly - years ago when the Corvette was introduced this was the adhesive made specifically at that time to glue the fiberglass panels - held with the grip of God so to speak. Then the uses for it got more advanced as you are speaking of. Lots of work is done with the 3M product.

Good luck on your decision and keep after your project - its never a waste of time when its all done and you can sit back and enjoy your hard earned labor in enjoyment.

 

[m16ty]

I read somewhere that a normal weld has a tensile strength of 1500 psi where the 3m panel bond has a tensile strength of 3,000-4,000 psi. So the Adhesive is plenty strong for the project I am working on Heck, Mercedes, BMW etc has some cars now that are almost completely glued together using this type of adhesive.

Thanks again..
Jeff

I think your figures are off a little. A good weld has around 70,000 psi depending on what wire you use.

Personally, I'd weld it. Either your machine isn't set up right or you need more practice or both. Do you know anybody close that could help you out? If I was closer I'd be glad to weld it up for you. Should be about a 30 min job.

 

[swbradley1]

Get 3M VHB tape.

http://solutions.3m.com/wps/portal/3M/en_US/3M-Industrial/Adhesives/Product/Bonding-Tapes/VHB-Tape/

and for welding........from another site.

Arc welding electrodes are identified using the A.W.S, (American Welding Society) numbering system and are made in sizes from 1/16 to 5/16 . An example would be a welding rod identified as an 1/8" E6011 electrode. The electrode is 1/8" in diameter
The "E" stands for arc welding electrode.
Next will be either a 4 or 5 digit number stamped on the electrode. The first two numbers of a 4 digit number and the first 3 digits of a 5 digit number indicate the minimum tensile strength (in thousands of pounds per square inch) of the weld that the rod will produce, stress relieved. Examples would be as follows:
E60xx would have a tensile strength of 60,000 psi E110XX would be 110,000 psi
The next to last digit indicates the position the electrode can be used in.

1. EXX1X is for use in all positions
2. EXX2X is for use in flat and horizontal positions
3. EXX3X is for flat welding

 

[m816]

Gimp, the avatar shows you can look a girl in the eye.

 

[Heath_h49008]

Get 3M VHB tape.

3M

and for welding........from another site.

Arc welding electrodes are identified using the A.W.S, (American Welding Society) numbering system and are made in sizes from 1/16 to 5/16 . An example would be a welding rod identified as an 1/8" E6011 electrode. The electrode is 1/8" in diameter
The "E" stands for arc welding electrode.
Next will be either a 4 or 5 digit number stamped on the electrode. The first two numbers of a 4 digit number and the first 3 digits of a 5 digit number indicate the minimum tensile strength (in thousands of pounds per square inch) of the weld that the rod will produce, stress relieved. Examples would be as follows:
E60xx would have a tensile strength of 60,000 psi E110XX would be 110,000 psi
The next to last digit indicates the position the electrode can be used in.

1. EXX1X is for use in all positions
2. EXX2X is for use in flat and horizontal positions
3. EXX3X is for flat welding

You just gave the data for STICK welding rods.


To the OP...

...what kind of machine do you have,
...what position are you attempting to weld (flat surface, vertical surface, angle)
...what is the thickness of the material you are welding,
...what is the wire you are using,
...and what are you using for gas.

Edit: what is the joint? butt, overlap, "T"?

If you can get me that info, I can give you exact settings for your welder. DO NOT go the 3m route. Don't give up... YOU CAN DO THIS. Welding is not some strange art you must learn in a cave over 20years by pure practice and guesswork.

I hope this helps a bit.

 

[plym49]

I agree that you can weld the reinforcements underneath your trailer fenders with better settings and more practice.

However, in the interest of time (you already seem to have more time in this job than you wanted), eliminating the possibility of moisture getting in between the patch panels and the fenders, comfort (not having to work upside down), to ward off the possibility of warping the fenders (leading to even more work) and simplicity, I would use the adhesive.

For those who wonder if the adhesive is strong enough, consider that the OP is just adding a reinforcement to the fender. So strength should not be an issue (although it is probably plenty strong).

 

[Flyingvan911]

You might consider taking it to a welding shop. I do this occasionally. My welding skills are worse than a caveman rubbing two sticks together.

 

[m16ty]

You just gave the data for STICK welding rods.

MIG welding wire is comparable as far as tensile strength goes though.

 

[hcso1988]

As heath stated, give us some more information on the project. Welder type, wire size and maybe a few pictures of the project set up. A solid weld would be 100's of times stronger than a fiberglass adhesive or whatever the product is. Practice is key. If its solid metal your welding, than it should be a quick and easy project. You've got plenty of people here to offer assistance.

 

[michigan4x4]

Thanks guys. I appreciate all the responses. I ended up using the 3m Panel bond on the patch panels and it worked great. Used self tapping screws to hold the panels in place to dry. Will grind off the screws before paint. Looks nice and clean. Unfortunately I don't have photos or I would share some. The trailer is currently at my buddies house so I cant run out and take any. Either way I am happy with the job. I know I could have welded the panels but as you all have mentioned, it probably has to do with lack of experience on my part, setting the welder improperly, environmental conditions etc.

I am a little late as far as your question goes heath...
using a Miller Millermatic 250 mig welder
Using .35 welding wire
75/25 gas mix
thickness of material is between 18 and 24 gauge I would think just by looking at it. It is solid and free of any rust.

The trailer tub is flipped upside down on saw horses so I was welding in the wheel well. 90 degree angles, butt joints etc.

I will try welding again. Just not on the wheel wells as they are done. I am going to try and weld some tie downs in the tub of the trailer. I just cant seem to get the welder settings right. It really seems simple while I am doing it. I did produce some nice looking welds from time to time and then it seemed like all went to H*** as I started burning through, and producing large gobby welds with holes and pits in them. Lots and lots of grinding.

I try not to get discouraged but every time I pull the welder out, it seems like I ruin my trailer with burn through and make a ton more grinding work for myself. Heck... The grinding wheels for the Makita and 3m discs for the DA get expensive!

I do appreciate all the help and advice. I will try and get some photos next time I am over there working on it. Should be this week sometime.

Jeff

 

[michigan4x4]

I think your figures are off a little. A good weld has around 70,000 psi depending on what wire you use.

Personally, I'd weld it. Either your machine isn't set up right or you need more practice or both. Do you know anybody close that could help you out? If I was closer I'd be glad to weld it up for you. Should be about a 30 min job.

I stand corrected.. You are right. Mig wire has a tensile strength between 70,000 and 95,000 psi. Wish you lived up here. I would have probably taken you up on your offer.

Thanks
Jeff

 

[Katahdin]

Untrained & novice mig welder here, but I've watched the experts on TV use .24 wire on thinner sheet metals. I welded in an 18 gauge patch this weekend outdoors with my Miller 211 using .24 and didn't have any trouble with burn through, the wind was a little breezy. I set my gas output to about 30psi, which I knew was a little high but I figure it didn't hurt outdoors.