Soldering Irons?

[mrFinpgh]

Part of my current project involves zinc tops to a bookcase and desk.  I've got the zinc laminated onto some plywood, and the corners are mostly formed. 

My understanding is that finishing the corners involves soldering them with some zinc solder and then filing that down to create a finished look. 

Where I'm running into some trouble is that I can't seem to get the solder to flow.  I'm using an Aoyue 469 60w iron, which is supposed to get pretty hot.  Even turned up all the way, it doesn't seem to be doing a great job melting the solder.  I've tried warming up the surrounding metal with a heat gun.

Anyone here have any suggestions about what I could do to get this to work?

-Adam

 

[Holmz]

 

[AlexThePalex]

I'm using an Aoyue 469 60w iron, which is supposed to get pretty hot. 

Your iron is way too small. That one is meant for electronics, not sheet material.

Video below explains the whole process.

 

[Bohdan]

You will need to deoxidize the zinc with a zinc specific flux. One that comes to mind is hydrochloric acid also known as spirit of salts.

Whether the iron is big enough for the job depends on the thickness of the metal but I would think that a 60w iron would be on the small size especially if your not experienced at that sort of work.

 

[mrFinpgh]

So is the size of the iron the core thing here?  I need a big piece of hot metal?

The iron i have now is small.  I guess I was under the impression that it got sufficiently hot for melting zinc solder.

What's the most economical solution for me to get this done?  I don't really plan on doing a lot of sheet metal work in the near future.  I did find one of those large copper/iron soldering 'chisels' on craigslist - it looks more like a fireplace poker than a precision tool. 

Thanks,
Adam

 

[AlexThePalex]

What's the most economical solution for me to get this done?  I don't really plan on doing a lot of sheet metal work in the near future.  I did find one of those large copper/iron soldering 'chisels' on craigslist - it looks more like a fireplace poker than a precision tool. 

You can rent one. Or find one used on CL.

You really need a big 'fireplace poker' like this. Metal conducts heat very efficiently so when you apply heat in one spot, it is immediately conducted to the entire sheet. Only solution is to make the entry spot big enough so the heat stays long enough in that one place to liquify the solder.

Succes with your project. Doing something like this for the first time can be a challenge.

 

[Holmz]

That american Beuaty is 550w. They may have 1000W units (??).

 

[Thunderchyld]

If you're just doing a couple corners, you don't need to go all the way up to the American Beauty, but you do need something a little bit bigger than that Aoyue.  A Weller 8200 soldering gun (140w max, and around $30) should be more than enough for your purposes.  That big AB is designed as a tool for large overlap seams, such as those found in metal roofing. 

 

[Cheese]

The iron i have now is small.  I guess I was under the impression that it got sufficiently hot for melting zinc solder.

What you're trying to do is heat all the metal surfaces being joined to the temperature that the solder melts at, and all at the same time. When properly done, the solder will flow smoothly across the surfaces and bond to the substrate.

While your present soldering iron is capable of melting the solder, it is not capable of maintaining the level of heat necessary in the metal item that you want to solder. You just need a gun that has more watts to solder sheet material.

Something in the 250+ watt range will probably work. There's an inexpensive Weller gun that puts out 200 or 260 watts. If I remember correctly, the 1st trigger position is 200 watts and the 2nd trigger position is 260 watts.

You'll also want to make sure that the solder tip is in the shape of a wedge rather than a point. That way you can put heat into both sides of the corner at the same time and then feed in you filler material while moving slowly along the corner until the seam is completed.

Just make sure the corners to be soldered have been cleaned very well with abrasive cloth and have been fluxed properly.

 

[vkumar]

This Weller has enough power 200/300 W to power through your job.
http://www.amazon.com/gp/product/B0...ue&ref_=ox_sc_sfl_title_7&smid=A1UMBRA5ZTBCX8

Or you use a butane torch made by Dremel or others.

Vijay

 

[AlexThePalex]

I used to have such a Weller soldering pistol people talk about above, and it really didn't have much power. It was just good enough to solder copper wires together, but more or less failed at everything else. I would not recommend it. It is only hot when you squeeze the trigger, and is not meant to stay heated for longer periods. Mine met its demise when I was using it quite intensly and it got so hot at one point it burst into flames.

There are soldering irons with a big tip that are very cheap. Like $15-20. I have one that's 50 years old, belonged to my grandfather, and still works very well. I've used it to solder iron and copper plates together for model building. It has the advantage that it stays hot and can transfer heat very well.

[attachimg=1]

I don't know how big the sheets are the OP wants to solder together, but one like this might work. I doubt the pistol will work.

 

[mrFinpgh]

Thanks, everyone.  I really appreciate all the input and ideas.  It sounds like my iron is underpowered and undersized for the task at hand.

The metal is 20ga zinc, and the corners are about 1.5" or so. 

I'll have to get my hands on a larger iron and see how that goes.

Again, really appreciate everyone's responses.  It's amazing how helpful this forum is.

-Adam

 

[IanB]

I could never figure out why my Weller gun never seemed to put out nearly as much heat as I expected.  I finally looked at the manual:  Squeezing the trigger all the way results in lower heat than part way.  Strange design.

 

[wkearney99]

I could never figure out why my Weller gun never seemed to put out nearly as much heat as I expected.  I finally looked at the manual:  Squeezing the trigger all the way results in lower heat than part way.  Strange design.

Given how heavy those things were I'd imagine it was better to have a full-pull provide a lower temp to make it easier on casual/new users.  Anyone knowing how to deal with heat options might likely also know how to handle the gun better.  My $.02 anyway...

 

[mrFinpgh]

Bringing this one back up, because apparently I'm still not getting something.

I picked up a soldering iron much like the one in Alex's picture.  It's 200 watts, heavy, and has a tip about 3/4" wide made of what looks like copper.

I spent about half an hour yesterday trying to solder a corner and the solder never flowed once.  I heated up the surface of the metal with a heat gun for about 4 minutes before I started trying to solder.

Here's the steps I followed:

1. plug in the iron and let it heat up
2. Clean the surface and apply flux
3. Heat the surface with the heat gun for a few minutes
4. Try to solder

I'm really not sure what else I need to be doing?  It certainly seems easy and logical enough. 

-Adam

 

[Bohdan]

I'm really not sure what else I need to be doing?  It certainly seems easy and logical enough. 

-Adam

Have you tinned the new iron? This is done by cleaning the copper tip, Usually with a file, to ensure that you have bright unoxidised metal, and as it heats up apply a copper specific flux and coat the tip with solder. The tinned bit is then able to transfer its heat to the solder on the job rapidly. If the iron over heats and the tinning changes colour and oxidises you have to repeat the tinning process.

You then clean the zinc, apply zinc specific flux, not the one that you use to tin the copper, and solder away. I think that you shouldn't need to heat the job with the blow gun unless the solder melts on the zinc and immediately goes hard so that it won't allow you to easily slide the iron along the zinc melting the solder.

 

[Cheese]

Bringing this one back up, because apparently I'm still not getting something.
I'm really not sure what else I need to be doing?  It certainly seems easy and logical enough. 

Did you lightly abrade the surfaces that will be fastened together?

You state that you're joining zinc sheet, is it actually zinc or is it galvanized? Using the proper flux is very important.

If it's zinc, here's something I ran across.
http://jardenzinc.com/techdata/Tech_Brief_Joining_Zinc.pdf

 

[Peter_C]

Instead of a heat gun, which doesn't get nearly hot enough, try a torch. Propane should work. You can even heat the tip of the soldering iron with the torch. Most likely it is a lack of heat issue.

 

[mrFinpgh]

Have you tinned the new iron? This is done by cleaning the copper tip, Usually with a file, to ensure that you have bright unoxidised metal, and as it heats up apply a copper specific flux and coat the tip with solder. The tinned bit is then able to transfer its heat to the solder on the job rapidly. If the iron over heats and the tinning changes colour and oxidises you have to repeat the tinning process.

Hmm..  I did not do this.  Would failing to do so have been sufficient to prevent the tip from transferring heat to the zinc?

I assume copper specific flux == the flux I would use to solder plumbing fittings?

You then clean the zinc, apply zinc specific flux, not the one that you use to tin the copper, and solder away. I think that you shouldn't need to heat the job with the blow gun unless the solder melts on the zinc and immediately goes hard so that it won't allow you to easily slide the iron along the zinc melting the solder.

I did use zinc specific flux and a zinc specific solder.  Part of what confounds me is the seller (rotometals) warns about overheating the zinc and melting it.

Thanks,
Adam

 

[mrFinpgh]

Did you lightly abrade the surfaces that will be fastened together?

I did.

You state that you're joining zinc sheet, is it actually zinc or is it galvanized? Using the proper flux is very important.

It is actual zinc.  It's the top for a bookcase and desk I'm building.  The solder and flux are both from the same dealer (rotometal) that I got the zinc from.

Thanks,
Adam