Hello Amy,

	I've used a desktop welder and it was as awesome as it was frustrating. When it worked well it was a fast way to work and produced very professional looking results. It was however prone to bunching if the Mylar wasn't taut as the welding horn drags a bit which can move the Mylar by the end of a weld, especially longer ones. This was my experience with this specific unit, others may be different. If the table the welder is on or the surface of the welder isn't very flat you can get light or heavy welds and even a mix. Many of these welders have or can be equipped with a unit that moves the welding horn up and down as the surface varies to achieve a more even weld but it's not necessarily 100%. That being said I'd still love to have one again as the end results are worth it. One thing to think about is how many axis you want to be able to weld on. Most I've seen are a single axis and weld on a fixed line. You can get ones, for a higher cost of course, that weld on two axis which provide more flexibility and can potentially do curves or allow you to work with odd shaped items.

	I looked into handheld welders last year, albeit lower to mid end ones, and ultimately didn't proceed. The cost of something half way decent with the specs to properly weld Mylar was approaching desktop ones and didn't seem worth it at that point. There were ones from China that came in cheaper but still high enough that I wasn't willing to drop a grand of my budget on a chance they'd be suitable. The main issue with handheld ones seemed to be the pressure and length of contact as this was entirely up to the operator instead of pre-set by the unit. Incorrect pressure or length of contact produces holes, burns, or weak welds. Dragging the welder to produce a solid line would need quite a bit of practice. Spot welds seemed to be the better option with handhelds. You wouldn't be able to seal up items but could protect them for handling and storage. There are a few different types of handheld welders. I can't remember the terminology off the top of my head but fixed ones that work like a drill press. I don't know if these would be exactly termed 'handheld' but fell into that category. They have the advantage of potentially providing a fixed weld depth if you have it set to a specific mil of Mylar. Also, in theory, you could lower the welding hold and slide the Mylar under the horn. This would work similar to a traditional desktop unit to produce weld lines but you still had the length of contact issue. There were ones that had a stand with a handheld welder attached on a cord. There didn't seem to be much advantage of these ones over the other two so I didn't investigate them much. The third was completely handheld. This was the cheapest option but also the most difficult to use. As mentioned, issues around pressure and length of contact arose. I had sent samples to a company to test out and spot welds produced fair results with line welds producing poorer results. To be fair this was their first time working with the samples I sent so practice might yield better results. I haven't completely ruled out the option but at this point I'm not able to devote that much of my budget to something that may or may not pan out in the end.

	Hopefully this helped!

William Shepherd
Collections Officer
Swift Current Museum
44 Robert Street West
Swift Current, Saskatchewan
S9H 4M9
Phone: 306-778-4815
Fax: 306-778-4818


-----Original Message-----
From: Museum discussion list [mailto:[log in to unmask]] On Behalf Of Amy Minger
Sent: January 23, 2018 7:49 AM
To: [log in to unmask]
Subject: [MUSEUM-L] Ultrasonic welder

Might anyone have an ultrasonic welder for sale or know of a source for new machines? Preferably desktop style with a weld length capable of larger polyester encapsulations.

I have also considered the handheld ultrasonic welder. Opinions regarding handheld vs desktop welders would be much appreciated!

Thank you,


Amy Minger
Archival Assistant for Conservation

 Arkansas State Archives
a division of the Department of Arkansas Heritage One Capitol Mall  |  Little Rock, AR 72201
Email: [log in to unmask]
office: 501.682.6905
fax: 501.682.6916
archives.arkansas.gov   
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