8- Why zinc bar tops can’t be welded or soldered on site.

A challenge facing the zinc bar top industry is how to address seams or joints in the field. Why can’t we weld the tops into one piece just like they do in France?

This discussion of seams has always puzzled me, as the world goes together with seams. I’ve checked many projects in many cities, and it’s safe to say that seams are a problem for all surfaces everywhere. Seams help buildings move and remain stable by allowing expansion and contraction, so they’re a necessary evil.

As a simple answer, tops can’t be welded together because the cores are not metal. 

What is welding?

Welding involves melting the base or parent metal together with a filler rod, usually of the same alloy. People have attempted to connect tops by using a filler rod that melts at a lower temperature. However, this method has proven to be ineffective and the resulting joints are extremely weak and discolored.

Most customers want a seam that is better than what is currently available in the industry. This is a valid point. Manufacturers should be looking for ways to improve.

To know why seams can’t be welded or soldered on site, let’s see how heritage products from France are made.

Real pewter sheets can be joined on top of a solid base. This is done by placing the lap joint in the middle. This is how Legos are stacked for strength. This gives the top the greatest chance for survival. 

Imagine trying to join two separate, cantilevered surfaces with the thinnest of wrappers on site. When both the core and the metal seams are aligned, it won’t hold up over time. If there is any movement that is dissimilar, a fix is needed. Elbows on the customer side of the counter help to encourage this movement.

They can easily fill, fair, sand, and polish the sheets because they use pewter as their filler rod. Pewter melts at a low temperature of around 450 F, making it convenient to use a torch on site.

Save Money with Zinc

Many cast bar top manufacturers avoid using pewter but still falsely claim that their products are made of it. They deceive customers and charge higher prices for products that are zinc.

You can take several approaches to determine if real pewter is being used for your project.

The easiest method is to reach out to 3 Spark by going to our website and sending a message. With our experience, 3 Spark can assist you in getting the right information and making a wise choice.

You can also order two samples from the same manufacturer in zinc and pewter to see if you can tell them apart. Do they show different finishes for zinc and pewter in their catalog or on their website side by side? They will probably try to persuade you to choose different finishes in various metals or use other sales strategies. This should alert you to the fact that something isn’t right.

You can also send a sample into a lab for testing. If you go to rotometals.com and search for “Metals Analysis Test” you can submit a sample for examination. If the sample contains 99% zinc it means you have been misled because true pewter is mostly tin.

Some manufacturers use bait and switch tactics to deceive customers and make more money. They don’t deserve your trust, money, or association with your brand. If they’re misleading you about their metal, which is the basis of their business, what else might they be concealing?

The primary metal being used domestically is zinc. It holds up much better than pewter for everyday wear, and it has the same great patina characteristics. It is the workhorse for the demands expected of large, commercial projects. Zinc has incredible potential moving forward in the industry.

Zinc has a higher melting point than pewter, and it is extremely hard to weld, especially on site in such a thin format. Apart from the fire dangers that exist from ignition of the substrate below, zinc filler rods melt at a higher window than most standard soldering tools allow.

Using different tin-based filler alloys makes the seam more noticeable instead of hiding it, as they react differently to patina. 

If damage should happen to your tops on site, you can service the piece without costly work to undo the affected piece if it is not held in place with solder.

Manufacturers struggle to reduce visible seams and openly discuss the metals they use for their products.

3 Spark’s Commitment

We only use material that receives a third-party certification separate from the manufacturer, and we can provide you with this documentation anytime.

We create tighter, better looking seams than any other manufacturer. This allows you to simply caulk the seam with a close-match silicone for easy installation and future maintenance.

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