Pagoda SL Group
W113 Pagoda SL Group => Body, interior, paint, chrome, and cosmetic items => Topic started by: SilverSpear on May 24, 2023, 04:25:17
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Hi guys,
So I decided to invest in a spot welding machine, but thought to ask the experts who have done their own bodywork and were able to duplicate perfectly Mercedes' welds.
Which machine did you use? I have read about a technique called "plug welding", but as an esteemed member here mentioned that it leaves a raised area instead of a sunken one.
I have also read about the Lanco Mk2 spot welder, which is a great contender. But upon watching a footage of someone welding with it, I realized that the spot welds might be too sunken and their shape too different to imitate those of Mercedes. Might be wrong though.
Really need proper advice here to which machine is the best of my application.
I am no expert to this, so please bear with me for a second and this is a question for the Lanco users: if this machine cannot generate the needed results because of the shape of the tips, can those be replaced with ones who can? I can even use the services of a machine shop to fab those.
Thank You
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Just do a search ( as I just did moments ago) with “how to duplicate the look of spot welds” and a number of different techniques pop up. These are generally multi-step procedures involving a spot welder, drilling, filling, grinding and punching. Many different techniques…
Best to get some sheet metal of appropriate gauge and practice until you get the look you want. May be helpful to have detailed photos AND measurements as a guide.
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I am in the middle of another restoration, on my '61 Alfa Romeo Giulietta and just last week had to replace an inside panel section that had been spot welded in place. Since I don't have a spot welder, I plug welded it. This means: drilling not-too-large holes in the new panel, spaced regularly apart, then welding the hole full of new steel/weld and so weld the new to the old underneath. Yes it creates a small raised area (depending on how much material you deposit) but that can be ground out to resemble the 'dimple' that a spot weld creates. That would be a lot of extra work though (precise grinding) so it would be more efficient and better to just get a spot welder, they are not that expensive. Now it may not always be possible to use the spot welder depending on the sequence with which the original panels were welded in.
In the photo you can see the first (top) two of the plug welds I did on the Alfa:
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What Cees is talking about is exactly what I have done and that is plug weld. If you are a very well seasoned expert, you can get the plug weld close enough to fool a few people. Otherwise, the problem is that if you grind away too much weld material, the weld joint could be weakened. No real way of knowing if you ground off too much. And the time and effort to do so is adds up very quickly. Mercedes used many more welds per panel than your typical US made car of the time. Ask me how I know.
What caught my attention about this welding device is that the two jaws don't have to be directly opposite each other. Just need to be in the same vicinity on opposite sides. With in reason, you could spot weld most of the repair panels together. I have never used the Lanco welder, so have no idea how effective it is. Just looks promising given the price.
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Just do a search ( as I just did moments ago) with “how to duplicate the look of spot welds” and a number of different techniques pop up. These are generally multi-step procedures involving a spot welder, drilling, filling, grinding and punching. Many different techniques…
Best to get some sheet metal of appropriate gauge and practice until you get the look you want. May be helpful to have detailed photos AND measurements as a guide.
Hi Michael, long time buddy...
Yes, I started with a search and this is how I came up with info on the different techniques (that I mentioned) to duplicate the spot welds. Also posted this thread after I've spoken to Wallace about his experience in welding.
I am in the middle of another restoration, on my '61 Alfa Romeo Giulietta and just last week had to replace an inside panel section that had been spot welded in place. Since I don't have a spot welder, I plug welded it. This means: drilling not-too-large holes in the new panel, spaced regularly apart, then welding the hole full of new steel/weld and so weld the new to the old underneath. Yes it creates a small raised area (depending on how much material you deposit) but that can be ground out to resemble the 'dimple' that a spot weld creates. That would be a lot of extra work though (precise grinding) so it would be more efficient and better to just get a spot welder, they are not that expensive. Now it may not always be possible to use the spot welder depending on the sequence with which the original panels were welded in.
In the photo you can see the first (top) two of the plug welds I did on the Alfa:
Yes, I have seen this technique, quite risky and time consuming. The margin of error is really low with it. Prefer to source a better mean of spot welding.
I thought to ask the good folks on this group about their experience with Lanco (those who used it). I did PM a member who did but got no reply as of now.
What caught my attention about this welding device is that the two jaws don't have to be directly opposite each other. Just need to be in the same vicinity on opposite sides. With in reason, you could spot weld most of the repair panels together. I have never used the Lanco welder, so have no idea how effective it is. Just looks promising given the price.
Wallace, it is a fantastic machine and again if all fails, I will simply purchase it and do some R&D on the tips until I get the spot welds perfectly.
You do know that you can also use one tip only to focus on each spot weld?
Another option I thought of is to reach out to the manufacturer and see if he can modify the tips for the perfect spot weld. Guess need to send him a sample to duplicate though. (Hope I am making sense here lol).
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It wasn't clear to me if you wanted information on merely duplicating the appearance of the original spot welds, or you wanted to actually weld panels together while achieving that look.
I have no such appearance of spot welds. In going through some older photos of the restoration, I'm reasonably certain that the spot welds on my car were filled and smoothed as my fenders/wings were not changed. I suppose on the next paint job, the filler can be removed and these weld marks revealed!
Some of the links you'll find in the searching will be merely for duplicating the appearance of the spot welds on panels already joined, not on joining new panels. It's not just Pagoda people that want to do this...
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Well, most of the panels on mine are not joined correctly, they are rather tack welded poorly, leaving both a damaged panel and chassis in the process.
I will be replacing around 70% of the sheet metal after thorough preparation of the chassis surface and spot welding the new panels correctly this time around.
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In that case I would definitely go for a spot welder, given the amount of spot welding that will need to be done.
It does not need to be so expensive it seems, check out this product available in the US and the mostly quite positive reviews with example photos. $170 plus sales tax:
https://www.harborfreight.com/240v-spot-welder-61206.html
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Yeah, I have seen this type, but take a closer look at the spot welds of the Pagoda, you will realize that you can only use it at 10% of the total work to be done unfortunately