Search found 6 matches

by Alex Cordesman
Thu Dec 10, 2015 7:53 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Tungsten grid construction
Replies: 9
Views: 7173

Re: Tungsten grid construction

I don't think oxygen exposure is an issue since I was using a jumbo gas lens and a 10 second post flow. Coloration is a good indication since tungsten will blue quickly in air. There is a small spot an inch from the weld that was outside the gas shielding. Since the break when it was flexed was at t...
by Alex Cordesman
Thu Dec 10, 2015 12:54 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Tungsten grid construction
Replies: 9
Views: 7173

Re: Tungsten grid construction

IMG_5220.JPG Yup, autogenous welding of tungsten is pretty straight forward. Pretty much the brightest thing I've ever welded but a fairly easy to control puddle. It was mechanically weak though and when I flexed the joint it snapped clean at the weld point after less than 10 degrees of deflection....
by Alex Cordesman
Fri Dec 04, 2015 6:13 pm
Forum: FAQs: Vacuum Technology
Topic: Diff pumps help keep the water OUT!
Replies: 2
Views: 6120

Re: Diff pumps help keep the water OUT!

So I've seen issues of water in the oil discussed several places here and it didn't occur to me until I saw the shutdown procedures you guys recommend written out. The diffusion vacuum systems at my lab are always stored at the vacuum limit of the mechanical pump. The only time they see atmospheric ...
by Alex Cordesman
Fri Dec 04, 2015 6:26 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Tungsten grid construction
Replies: 9
Views: 7173

Re: Tungsten grid construction

I didn't think the neutron density was high enough to be a huge problem but it is far enough outside my bailiwick that I wanted to float the question. I found some discussion on welding tungsten on a different forum and it seems fairly doable. With a ceriated 1/8 electrode in the torch running DCEN ...
by Alex Cordesman
Thu Dec 03, 2015 10:04 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Tungsten grid construction
Replies: 9
Views: 7173

Tungsten grid construction

I was looking at some of the grid designs and was wondering with tungsten grids how they were being put together. For most other materials I'd just TIG it all together and be done with it. Are those of you that are using tungsten soldering/brazing it together with a dissimilar metal or are you TIG w...
by Alex Cordesman
Tue Dec 01, 2015 10:22 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Quick Question on Welding Costs
Replies: 4
Views: 3494

Re: Quick Question on Welding Costs

Sorry if this is listed elsewhere, I think I saw it but I'm having trouble finding it again. For TIG welding the 8" CF Flanges to the 6" hemispheres, and adding in 4 half nipple 2.75" CF flange ports in a standard configuration, the shop on my campus quoted 30-40 hours at $1500-2000. Is that a reas...