Lead free solder ????

[67 455 Bird ragtop]

I plan on welding up and smoothing out some seams. I read several threads about the expansion rate differences causing the seams to appear in the heat but disappear whne the body cools off. Most people recommend welding then using lead to fill tyhe seam like the factory originally did. While I have never worked with lead before I know the theory and precautions to take.

My question is will the newer lead free solders do just a good a job as real lead in preventing this problem with seams ??? Or would an all metal filler work ???

[spoilersbyrandy]

Here is a picture of my 70 El Camino, I installed a new top and filled the seams with eastwoods lead free solder. I have used regular lead in the past with good results. The lead free is claimed to be stronger. I have used All Metal and had it crack in 8 to 10 years.
https://static1.pt-content.com/images/pt/2010/04/myElCamino043-1.jpg

[nullshine]

Removed

[JRouche]

Hey guys,

I've got an '88 Cutlass (RWD) with a vinyl top.
I'm wanting to remove the vinyl top, however, there will be small holes around the perimeter of the rear window. I would just MIG them shut, but I'm afraid of cracking the rear window, I'd also like to avoid taking the rear window out at this point.

Would the solder fill the holes (they're probably about 1/8" diameter) well enough, and stay at a low enough temperature to avoid damaging the glass?

I realize that technique would play a large part in this as well, but I'm just curious if it's going to be significantly better than MIG welding about an inch away from the rear glass.

Cheers,

-James

Id be concerned that the holes are not just the tip of the ice berg. The vinyl tops are common for holding in moisture and causing some serious damage. If you think the holes are just that, small holes without any underlying serious rust then you should feel comfortable poking around the holes with a punch. An automatic center punch is the tool I like. It will leave a small divot on strong metal. Easily covered up. But more importantly. It will reveal some rotten metal quickly. If you think the punch will bust through because the metal is rotten then just filling the holes with metal is like putting a bandaid over cancer. Cancer needs to be removed or it continues to grow and will kill the car.

If the metal is still secure then Id mig weld it. It would be a whole lot less heat than laying down some lead.

The heat affected zone. The HAZ is looked at with the base metal being a consideration. So you are looking at one metal. So thats a constant. Then the processes come into play. Soldering, brazing, oxy-act brazing and welding, MIG welding and finally TIG welding.

I have come to find out the processes shrink in the HAZ from the first to the last. Soldering, which is like leading a car body has the largest HAZ. And I wouldnt close a hole with lead soldering on a car body.

The heat applied is lower for leading, but its still around the 850* mark for a good leading in work. Thats gonna be a large portion of metal around the primary section you are leading that will get to that temp.

Oxy-act brazing will be just above that temp but still have a large HAZ. Oxy-act welding will be an even higher temp but will be a structurally stronger joint for some applications. But brazing is pretty darn strong for certain applications. With the advantage of a lower heat. Think carbide saw blades and some lathe tool bits..

Then you get into MIG welding. Much higher heat, but more focussed on the work. High heat to melt the filler and base metal. The advantage? Crank up the heat to the point of instant liquification of the filler and base metal then remove the heat source. You get a fast melting of the two parts then get to stop the heat transfer. Smaller HAZ.

Then there is TIG. Still a very high heat. But its even more localized. If you are good and fast with the torch. On car body panels most guys can get in and out faster with a MIG torch. But an experienced guy with a TIG torch can use less heat and localize it to get a smaller HAZ. It may be only the diff of a 1/8" HAZ, but sometimes thats all thats needed.

For an example. I can run a bead on a joint of two pieces of pristine metal with the TIG and not even use filler and the HAZ will be very small. Where if I used the MIG it will use filler (more heat needed at the joint) and the HAZ will be larger. Prolly three times the HAZ on 16ga steel.

So.... My point. To lead in the area around the window you will be heating up alot of metal. And the window seam, where there is rubber, it will get pretty hot. If you zap it with a MIG welder the heat will be localized to a much smaller section. Wont even get to the window channel if its more than a 1/4" away. The leading will heat ALL of that area up, more than three inches in all directions. Again. I woulding use lead to close a hole. JR

[nullshine]

Thanks for the reply, JR.

Sorry, I should have mentioned that the holes around the perimeter of the rear window aren't rust holes, they're punched holes for rivets, which hold on a trim piece. The vinyl is wrapped onto the trim piece, then the piece is rivetted on, then the vinyl top is glued onto the surrounding metal, creating a kind of a rolled edge of vinyl near the rear window. I don't have any closeup pics of where the vinyl meets the window, but this'll give you an idea of what I mean:

https://static1.pt-content.com/images/noimg.gif

However, you're correct on the vinyl holding moisture and causing all kinds of nastiness... There very well may be some rust lurking under there. It's half the reason why I want that vinyl off of there.

Your information on the heat-affected zone is very helpful. I figured the lower temp of soldering would keep me safer, but if its spread to a larger area, all bets on that are off. I guess a quick zap with the MIG is the way to go. I guess I'll just protect the rear window from spatter somehow or another (maybe some nozzle dip?) and give it a shot, letting things cool in between. I do have a spare rear window if things go horribly wrong, but I'm thinking most of the trouble that could be caused would be by burning the sealant, not cracking the glass. Hopefully I can get in there with a copper strip from inside the car to back up the hole, that would make things easier.

Thanks again, JR. If you've got any ideas or anything else to add, I'm all ears.

[JRouche]

I guess a quick zap with the MIG is the way to go. I guess I'll just protect the rear window from spatter somehow or another (maybe some nozzle dip?) and give it a shot, letting things cool in between.

You are thinking about the correct stuff. Spatter on the window is not a good thing. What I do, if Im working on a car or other piece that needs welding is use welding blankets. If you have a harbor freight near by their blankets are not great, but do keep the splatter off the car and they dont burn through with even a large glob of molten metal. As long as it doesnt sit there for too long burning through.

They are inexpensive enough that I have cut them up to use them for custom blanketing situations. On your car. I would drape them like you see in surgery movies. Thats one of the reasons I cut them up. They have a thick outer seam. I remove that and tape the edge of the now thin blanket right up to the edge of where Im gonna weld. I just use painters masking tape. Any splatter will roll off the blanket to a lil cooled ball of metal. Id drape the entire rear, the window side. And any other parts of the roof you dont want splatter to affect.

Though... I dont think you will get much splatter at all. Not like you are running a hot and heavy bead. Just a spot weld sized nugget. A high heat and semi slow wire feed will keep the splatter down for a quick spot weld. Not so slow of a wire speed so you are melting the wire before it gets to the puddle and dropping off balls of melted filler. But slow enough so you are laying the filler into the very hot puddle at a slower rate and not pushing the filler in causing some back flash (splatter). Keep the puddle hot and molten and the filler speed slow enough that it just melts when it is at the top of the puddle. Its kinda like dropping a ball of melted filler onto the top of the molten pool. Not above the pool though, but right at the top surface of it.

And I have to clarify. This is not how you would weld structural members. But for body panels, just a small hole it works great. Produces a solid spot weld that will have enough metal to be able to sand down to the surface of the body panel.

For structural welding of frame members or any other structural pieces you want to dive the filler into the molten puddle, really want to push it in there to just below the point where the fast introduction of cool filler does not cool the puddle. If it is too fast then the puddle cant handle the in flow of filler, it cools the puddle. Thats why I use as much heat as I can. Keep the pool very hot so I can stuff in the filler as fast as I want to. I try to keep the filler tip as close to the bottom of the pool as possible. Just short of bouncing the tip off of the bottom of the joint. So say you are welding 1/8" steel, the tip of the filler is deep into the pool and about 1/32-1/16" away from the back side of the joint. Just so its not bouncing off the back side of the joint, but also so it IS well within the pool of molten metal. Kinda hard to explain. But you want the electrode (filler) to be in the center, or a lil below center of the molten pool. You can get a feel for it if you use the welder alot. And I do more TIG welding than MIG. But the feel for where the filler is melting within the pool is about the same. Solly, I went off on a tangent :)

But DO protect the window. Oh, and I dont like the anit-splatter sprays. They will keep splatter from sticking on metal surfaces but they dont have any heat protective qualities. So if a ball of splatter lands on a piece of glass and happens to not roll off then the heat will make a scar on the glass.

Solly for going on and on. I love to weld and talk about it. Im not great at it, but I still like to weld. Oh, and obviously talk and talk. JR

[nullshine]

But DO protect the window. Oh, and I dont like the anit-splatter sprays. They will keep splatter from sticking on metal surfaces but they dont have any heat protective qualities. So if a ball of splatter lands on a piece of glass and happens to not roll off then the heat will make a scar on the glass.

Solly for going on and on. I love to weld and talk about it. Im not great at it, but I still like to weld. Oh, and obviously talk and talk. JR

Thanks for the advice!

I know what you mean about the anti-splatter sprays... they're thin like water, sure it prevents stuff from sticking to a nozzle, but I wouldn't trust it to dissipate any heat, as you said.

What do you think about the nozzle "dip"? It's about the same consistency as vaseline, so it could be applied thicker than the sprays.

[JRouche]

What do you think about the nozzle "dip"? It's about the same consistency as vaseline, so it could be applied thicker than the sprays.

Messy... To slather the window with basically grease to shield it. Lay a welders blanket down.

Cant afford that. Lay down water soaked blankets. They wont catch fire and will protect the glass. Get them for practically free at the salvation army, or goodwill. Lay down a heavy water soaked blanket, bed spread or something. When yer done welding just pull it off. JR