gluing together a late model as it was designed to be done by the engineers at Mercedes and filling trim holes in a door on some vintage tin is like comparing donuts to dinosaurs. welding a plug in or just welding the hole shut if it is small enough is the only right way to do it. with a little practice it will be undetectible even in bare metal. you could even do the backside if you wanted.
I had 2 bigger holes on the rear pan of a 47 ford coupe' used 2 nickles they worked perfect and now the car will always be worth something ...lol I love these kind of threads.
If they filled trim holes with glue, and painted over them, you would have seen it already.... No factory, or reputable body shop is going to fill trim holes like that, and you will find out why after you paint it.... Every manufacturer is gluing door panels and roof panels on. None are filling holes with it, just you, and that dont make it right. You are telling folks that its OK to follow your method, even though you havent tested it. What you really are doing, is costing someone alot of money in the end. I think thats chicken shit.
You won't see any car manufacturer bond two flat panels with a lap joint in the middle of a visual panel as was done on the OP's door. So that argument is out. You also won't see any manufacturer glue a hole shut with adhesive and a metal backer. So that argument is out. As you say, donuts to dinosaurs. You can get the glue off the Mercedes line, and mis-use it, and have problems. Why dick it up when sure methods exist?
I worked at a Mercedes dealership as a collision tech for over 20 years. NO mercedes had exposed glue joints like you describe. Structural adhesives are designed to seal and lock hem and flange joints to increase stiffness. In a true structural location they are combined with normal weld procedures to increase torsional etc rigidity. They also work great to seal the flanged area completely from water and dirt penetration...but thats not the primary goal. The key to those adhesives is to have the joint as tight as possible. I mean extremely tight, not just close. I've seen people try to do things by using the adhesives as a filler much the same as you describe, but I've never seen it last too long. Alright for a rusty old beater thats getting slapped together and filled over with a proper bodyfiller, but simply sanding the adhesive and using it AS the fill? I've never seen it work out. I'm sure theres the odd job that lasted...just luck will get you there sometimes...but as a planned repair? I wouldn't take the chance based on what I've seen first hand OR my usual luck with LUCK!
I filled some rustout in a Model A door with with body panel adhesive. That was 10 years ago and it still looks perfect. The car is painted gloss black BTW.
I got a PM from another HAMBer who did this exact same thing 9 years ago on a pro-street nova..........his words.....go for it ...no problem. He didn't want to become part of a pissing match that we seem to have. As for why we did it, here goes. We replaced the door skin on the passenger's door of our 51 ( I'm sorry to offend, we used the wrong tail lights on the car ) fleetline. There was no rolled edge at the bottom of the skin so something was needed. We could have welded in another piece of metal but then we would have been chasing the warp-age. After a lot of discussion we decided to try using the 3M product to affix the new piece of metal to the bottom of the door skin. Once we had affixed the bottom piece and were very happy how it turned out, we decided to use the adhesive to affix the door skin to the inner structure. We called the 3M tech line and explained what we were doing and the kind of outcome we were looking for. 3M said what we had described would work as long as the pieces were tight against the main panel. We followed their instructions to the letter. Each small piece of metal was held in place with long reach vise grips until it was cured. Will it last ? Who knows ! We felt it was worth the time and effort to at least try it so we did. We are in the process of pie cutting/ sectioning the hood on the same car. GUESS WHAT ? We are going to glue it as well. We are going to use aluminum rivets in the glue joint flange area and grind them away when finished. So there you have it ! 3M says it is OK ! Several HAMBers say no. Several other HAMBers say they have done the same thing and it is OK. IT is basically the same as JB Weld...which I have used on my car.......on the intake manifold, on the header flange and on a few pieces of the grille on my car. No shrinkage or problem so far To the guy who started this thread about using nails, sorry your thread got hi-jacked. I didn't mean for that to happen.
You guys ever try soldering in a small patch? Everything has to be super clean and fluxed just like anything soldered, works for me.
That's for sure! A few years ago, I was on the passenger floor holding a penny to the firewall as my buddy wielded the welder to fill a small hole in his Plymouth's firewall. The welder blew through that penny like it was a Kleenex and ignited the carpet padding. The fire was quickly extinguished, but my buddy still likes to kid me by imitating the squawk I let out when the penny dissolved. After that, we cut out pieces of appropriate sheet metal to fit any holes.
I don't see anyone starting a "pissing match"....I just see you being somewhat sarcastic in your responses to being disagreed with. I certainly wasn't trying to start or be part of a pissing match. My intent was to add relevant info! I was responding to your remark about "glued together" Mercedes cars because I have over 20 years experience with them, and you were misrepresenting the facts about them to further YOUR argument! By the way...."Paintable" doesn't necessarly mean that the product is designed to be in clear eyesight and to be perfectly smooth under a buffed panel. It simply means that paint won't be rejected by it. Think automotive seam sealer compared to silicone sealer. The plan here was for 3M to let Professionals know that any squeeze out from the joints could be easily cleaned off while wet and after curing the seam edge could be paint blended just like regular automotive seam sealer without additional bodywork procedures being applied. EG: Most modern cars use a roof panel that has NO smoothed joint to the adjacent panels, just a channel that is closed off with a moulding. By using the glue, you eliminate the need for repairing the weld areas you would have needed otherwise and the paint from the new panel can just be sprayed out past the glued area. Thus the "paintable" part. The mouldings then hide the glued areas...no paint blending to adjacent panels are required (as long as the color match is good of course.) and no visible seams are present to shadow thru the final finish due to he normal expansion/contraction cycle. 3m isn't saying you can glue a flush patch in the middle of your actual roof panel and then use the glue as permanent bodyfiller without any issues at all! I'm sorry....they just aren't.
I go the cheap way out myself! I use the left over wire from the finished spool of my mig welder. just fold the wire until it gets to the size of the hole you want to fill, stick it in at an angle and keep pushing it as you weld. No fuss no extra cost. now all of that scrap wire is good for something!!!
I your ride is all original, with the original trim in decent shape, I don't think it's a good idea to permanently fill the holes. If you found your "Dream Ride" and needed to sell your rod to fund the new build I would think it would be a selling point that the new owner can simply punch out the covered orignal trim holes and re-insert the moldings!!! I'm just say'n.....
Rad! this thread went from metalwork to life size plastic model kit in 3 pages! I filled about 70 spotweld holes today with a welder and a good old piece of copper backing. Bigger holes I use plugs... I've used chads from my wirth sheetmetal punch like mentioned earlier. if warping is an issue take time between , grind very carefully and practice metal bumping. gonna be way nicer than overlapped pop riveted glued panels.
I always weld the other side. If you wouldve welded the other side, you couldve used a flapper wheel and pretty much metal finished it and it would require almost no filler. If you hold the copper on the side that a grinder cannot get to, then you dont have a big blob of metal inside. Am I going abou this wrong?
I have been using acid core solder and a propane torch since I went to tech school in the early 70's..works great on holes 1/4 or smaller...
Providing some real-world feedback to this older thread. About 8 years ago I built a project car and part of that build included patching some holes originally used for body cladding fastening locations. First, the back side surrounding each hole was whizzed down to bare metal, as was the hole opening. I touched each hole with a counter-sink bit from the outside, just to make sure the bare metal extended from the inside to the outside. I snipped up some ~3/4" square patches from sheet metal and bonded them to the back side using 3M 8115. I taped the patches in place while curing, trying to make the bond gap as thin as possible. The car was then fully finished and painted. Eight years later, there is no evidence of any of the holes that were filled. I even just went now and re-checked out of curiosity.
Come to think of it, I used this method to stabilize my chop, but there I screwed on a band of sheetmetal from the inside & cut of the tips of the screws from the outside. It made it very uniform, even & stable when I welded the seam. It's probably been about 7 years & I can see no shrinkage or cracking in the least.
An old body man show me a round lead cone that you push into a say a chrome trim hole after you removed and tin the metal around the hole. You than heated around the lead, staying on the metal. The lead would melt and mold into the back of the sheet metal. You would then let it cool and file the front down to a uniform finish, prime and paint. He told me at one time he did filled many trim holes on many cars while the de-chroming stage/fad was going on. The only thing he regrets is not saving all of the stainless steel trim he removed.
OK, gotta add my 2 cents in here. I have been working on a car that was started by someone else, who did this"trick" to fill holes. The car had been in and out of different shops for a couple years ( upholstery, radio, exhaust, etc.) By the time the car got back to me, a bunch of the 'nail filled' holes had cracked. The car had never been on the road, only trailered shop to shop. I wound up tracking down as many of the nail holes and getting rid of them and doing it with copper backing with a MIG. My idea on why it failed: the nail is thicker than adjoining metal (a bad thing in the first place) so if using a heat setting on the MIG to weld them in, without blowing holes in the surrounding sheet metal, it will not be hot enough to make a GOOD penetration to the nail. I had some other theories, but this on seemed to fit best. So I wouldn't recommend this method of filling holes. Another reason not to, is that if you want to hammer out any warping that the welding makes, you can't do it with the thicker nail heads in the way. Another is that sometimes the back side is sticking through too much and can be a place for mud, salt, etc. to collect, and prematurely rust it from the back side, if not thoroughly coated.
Everyone to their own choice but my TIG and 3 MIGs gather a lot of dust anymore. If bonding agents are hold together super sonic aircraft and Chevy truck door hinges then they're good enough for my 60 to 80 year old junk. Recent photos of patches and construction panels from 2003, 2007, and 2008. I guess since Texas temps only range from 100+ to around 15 it hasn't had time enough to start all the shrinking and cracking. The 31 A had the top glued on and the POS Gaslight fenders sectioned to resemble a real Model A fender plus weather strip channels for the door weather strip rather than the doors overlap shingle style like factory. I use 3M and Marine-Tex depending on the situation. When buttered up sufficiently to where it squishes out all the way around it's a 100% waterproof joint something just about zero welds are. The top filler took 24 hours to do with NO WARPING; how long does yours take? Also 49 Chevy PU firewall, 48 Chevy PU filled hood.
Small trim holes don`t have a lot of surface area on the edges, so if you are using a panel bonder to fill a trim hole, best to back it up with some form of composite material. It`s fine and will hold, but for this board and traditional methods probably veering away from the intended ideals?
I haven't tried it yet, but I am planning to use panel adhesive to attach sheet metal tabs to the backside to fill the trim holes on my current project. The reason I favor panel adhesive is that it seals all bare metal against moisture. My plan is to lightly feather around the holes on the front side after the adhesive has dried for a smooth transition with no exposed adhesive. A very thin wipe of filler will level the feathered edges. Theoretically, since I won't be painting over any adhesive, I can prevent the shrinking and cracking problems. Has anybody on here done it this way?
You can do it any way that you want. Not a method that follows normally accepted procedures. Personally, I think your theory is quite flawed.
The Jalopy Journal
