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km987654 · Posted: Thu Sep 03, 2015 6:54 am Post subject: Barco 909 & 1209s LC tanks Help

Ok so I have been after a set of these for my next project and finally I have some but here is the thing I am really surprised as these tanks don't have any expansion ability. I have been using Sony G90 LC tanks and also Sony 1292 LC tanks and also older Barco tanks and I also have some Ampro LC tanks all of which have some sort of chamber to allow for expansion. So what gives (or not if you know what I mean) doesn't glycol expand in Barco LC tanks? Also these LC tanks would need to be absolutely full to cover the tube face so I can't see how you could even leave an air gap.

Mounting the tube in these LC tanks seems interesting. On all of the other LC tank types mentioned above silicone can be placed around the face of the tube to seal it but these tanks don't have a surface for the tube face all the way around so you would have to seal the side of the tube it seems. Perhaps someone could help with the right procedure for this. Shocked

gnnash · Joined: 10 Jul 2013 Posts: 216 Location: Lake Elmo, MN

Mine are indeed sealed on the side, as you suspected. There's a lot of sealing volume there, I ended up putting the better part of a whole tube of silicone in the housing for my green tube.

I also expect that the rubber bellows are what allow for expansion in these tanks. I left a sizable bubble in the top of the chamber. You are right, the bubble does touch the tube face a bit, but is well beyond the phosphor, which is what you are worried about cooling.

Think about it - on a marquee or whatnot with a sealing surface on the front of the tube, you aren't getting glycol touching the face where things are sealed, so a bubble well beyond the phosphor at the top of the tube face isn't going to hurt anything.

**Curt Palme** · Posted: Thu Sep 03, 2015 1:52 pm Post subject:

After the nightmare trying to take Marquee tubes out of LC chambers with silicone on the front edge of the tube, I don't do that when resealing Barcos. As Nash said, you use a LOT of silicone (not as much as Marquee housings though!) to reseal them. The trick is to use a plastic straight edge to force the silicone down around the tubes, as air bubbles form, and then usually cause leaks out the back. Force the silicone down, create a smooth surface all around the tube, make sure there's no air bubbles, then let sit for a week.
After wasting a bunch of glycol, I then fill the chambers with water, and let them sit on each side of the tube for 6 hours on a paper towel, checking for leaks. If no leaks show up, only then do I fill with glycol.

gnnash · Joined: 10 Jul 2013 Posts: 216 Location: Lake Elmo, MN

My barco tubes never had silicone on the front edge from the factory either, it would take a ton to fill in around the front, and I don't think it's a good idea - as Curt says, it would be a nightmare to remove if you did that.

I cut the applicator end of my silicone tube into a wedge shape, so I could sneak it down between the tube and housing a bit when filling. Didn't shove it down with a straight edge, but did push it down and smooth it in with my finger a bunch. I had to do this twice because my first replacement was defective, and didn't have any air bubbles in the silicone when I took it out, and no leaks either time.

Oh, another thing. Be sure to spray the housings with black epoxy paint if you scratched the ceramic coating in any way at all, to avoid fungus or discoloration. I used black appliance epoxy paint, and let it dry for a week before sealing the tube in.

**Curt Palme** · Posted: Thu Sep 03, 2015 2:12 pm Post subject:

Also make sure those plastic spacers are on the front of the tube housing. That allows some 'give' as the tube expands when hot.

km987654 · Posted: Fri Sep 04, 2015 8:23 am Post subject:

km987654 · Posted: Fri Sep 04, 2015 8:28 am Post subject: