I’m sorry I’ve not been able to provide updates more often, I have many projects going at once, on top of a very busy work ‘life’.. I wouldn’t call it a life, at work, but I guess that’s the terminology 😛 If you’re following these posts, please feel free to post a hello below.

I received the supplies to build the tube furnace for the CVL laser, I’m hoping that this furnace will be suitable for the CuBr and CuCl version of the laser, as well as the elemental copper version of the laser.  Time will tell, but for right now I am focusing the CuCl/CuBr version. I still haven’t decided on the particular source which is why I say CuCl/CuBr at this time. I’m sure as I get closer to a working laser I will decide on the type.

Right now I have been working on the tube furnace.  The furnace consists of a piece of 6 inch black thick steel stovepipe which I purchased at the local (NOT ACE, Mr. Argon Ion) hardware store.  This piece seems suitable for my needs, it is a thick wall, it’s sturdy.  One of the unfortunate side effects is that it suffers quite a bit of expansion/contraction of the material under heat.  I’ve been using my oven to dry out each layer of refractory ceramic mortar I am using to build up the unit and separations are forming at some of the seams.  When they do I just fill with more mortar and they eventually go away.  It is something to be aware of if you use this method.

As I mentioned in a previous post I ordered a bunch of the refractory ceramic supplies from Ellis Knife Works, they seem like a nice couple and were in contact with me a decent amount regarding the availability of supplies and status of my order.  In short time I received the refractory components which consisted of the Inswool ceramic fiber mat, the Insboard ceramic fiber hardboard, and the AP Green #36 refractory ceramic mortar, and the ITC-100 refractory ceramic mortar.

I cut the stovepipe in half using a skill saw with a metal blade, this has to be the noisiest thing I’ve ever heard, and it’s great that I own a house now. Trying to do that cut in an apartment would have resulted in the cops at my door and glares from neighbors who idea of a project is gluing plastic flowers to a painted board.

I used my electric scroll saw to cut out the shapes in the ceramic board (Insboard) to fit the ends of the stovepipe.  It’s important to avoid breathing the dust from ceramic fiber materials as they are SUSPECTED carcinogens.  I use a vacuum with a HEPA filter to suck up all the nasty junk as I’m cutting.  These materials, in particular, contain crystallized silica (quartz) and in a fine powder they are suspected to have the same carcinogenic affects as asbestos.  Always be safe when working with such materials, you can never get some parts of your body back.

Here are some photos of the tube furnace in progress and my messy workbench.  While I have proceeded further than this I haven’t taken pictures.  I will be taking pictures of the process I used to build the top half of the tube furnace, so you can get an idea of the sequence.

Update: I’ve added a photo of my current progress, in the top of the photo you see the furnace half with the Inswool installed and coated in the AP Green #36 ceramic mortar, and in the bottom half you see the steel shell being prepped for it’s layer of Inswool mat/blanket.

Make sure to check out the follow-up to this project on my site Jon’s Hobbies to see how the laser worked out!

tube furnace progress

tube furnace progress

AP Green #36 Cermic Mortar

AP36 Refractory Ceramic Mortar

insboard ceramic fiber board endcap

cluttered workbench, cluttered mind

test fitting the insboard ceramic ends

Securing the endcaps in the stovepipe

drying out ceramic mortar


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