Saturday, October 2, 2010


If you have information about the costs involved with rebuilding, please share it. What materials are involved? What do they cost? How much gas is used in to heat the glass and run the oven? What are the electricity costs?


  1. I have zero experience. But, you'll need guns or have them rebuilt by Southwest. Getters, which are available from a number of suppliers. I assume Scotty is giving all the equipment, including a CD welder, which you'll need to attach the getters. You'll also need an assortment of glass tubing for the necks.

    The gas usage would depend on the efficiency of the oven so Scotty would be the best source of info. The electricity costs should be minimal. I think the heater for a diffusion pump is a couple of hundred watts. The motor for the mechanical pump is probably around 1/2 horse.

  2. I forgot to mention the one cost I know about. I had an odd ball gun rebuilt for a 12VP4. It was about $100 to have that done. Normal guns would be significantly less.

  3. According to Bob Wolfkiel at SW Vacuum, guns range in price from about $12 to about $65 for a 21 inch color roundie gun. Scotty had a stash of neck glass for older B&W tubes but the supply of 012 Lime glass for 21AXP and 21FBP is limited. Corning no longer produces 012 melt. Schott might be able to provide it, or perhaps RACS may know of a source. I think there is a pretty good supply of the diameter for B&W tubes comming from Scotty, but the larger stuff for the color crt's will be in limited supply unless we can find more. I believe it is 51 or 52mm for the color necks.

    I would recommend only running the ovven when we have a full house of tubes to evacuate. Especially if we are running the 6 hour cycle for doing metal tubes. The oven has 2 8 foot long gas burners. My guess is that it would be equivelant to about a 500,000BTU gas furnace. I dont think it would cost more than $10 to $15 per cycle to operate. The oven walls are 3/4" refractory board, 2 layers thick. Even then, when theoven reaches 600F it radiates a tremendous amount of heat. The oven should be placed at least 6 feet from any combustable surfaces. I would suggest that any walls nearby be 5/8" drywall or metal.

  4. Correction, Guns range in price form $25 for old style B&W to $65 for color.

  5. Rebuilding prices..... There is no doubt in my mind that the price we will need to charge to rebuild crt's will be quite affordable for the collector community. I would gladly pay up to $125 to have a B&W crt rebuilt. The cost of materials is going to be less than $50 for guns, getters, glass etc. Add overhead for utilities, and insurance and you still end up with a reasonable selling price. Remember, we are not going to make a livelyhood from this like Scotty needed to.

  6. It cost me $60 to have a standard 12LP4 gun rebuilt. But that probably also included Shipping both ways between Scotty and SW.

    He was out of slant guns, which is why I had mine rebuilt.

  7. The pricing information I got on guns was from Southwest Vacuum when I did the evaluation of Scotty's gun inventory.

    John Folsom called today and confirmed what John Yurkon said. Old style slanted beam guns for use with ion traps in non-aluminized tubes like a 12lp4 and a 10bp4 are no longer in stock at Southwest.

    John Folsom is going to speak with Southwest again to see what a production run of new slant beam guns would cost as opposed to having the old slant beam guns rebuilt.

  8. One of my concerns going forward on this project is the availability of materials, notably the guns needed for rebuilding a CRT. I spoke to Southwest Vacuum Products, which have supplied Hawkeye with guns and serivces. They have about 70 of the color guns needed to rebuild 21AXP22s, 21FJP22s ansd similar tubes. Cost per guns is around $60. They don NOT have the "slash" or "bent" guns needed to rebuild CRTs with ion traps, such as 10 BP4s and 12LP4s and similar tubes. These guns can be rebuilt by Southwest Vacuum at a cost of about $70. As for the "straight" guns, for 10FP4s, 12KP4s and similar, they have 6 in stock for $65, to build more from scratch $85.

    Scotty at Hawkeye has about 15 "slash" guns which he has removed from CRTs and kept as potential rebuild candidates, and these will go the the ETF. I think he said he has one rebuilt slash gun. He said he has a couple of the straight guns, but no more. He does not have getter materials for the B&W guns. He does have antenna getters for the color CRTs, though I am not sure these are appropriate for some of the early color CRTs

    In light of this, and given that there is no certainty that Southwest Vacuum Products will continue to be able to provide guns and services into the future, I would urge that the CRT rebuilding governing body seriously consider buying some guns an gun rebuilding services from Southwest as soon as possible. Stockpiling getters for the guns should also be considered.

    I have a half dozen 21" color guns which I will send to the ETF to add to the stock. These guns will need to be cleaned in solvent and have new getters installed.

    I think it would make sense to ask all the interested parties to search in their area for sources of guns to support this project. Closed/retired/still-in-business CRT rebuilders would be a likely source.

    One other note, I don't think neck glass is going to be a problem. Scotty has stock, and I have a good bit which I can send to the ETF to add to their stock.

  9. Someone has just donated 7 cases of NOS guns, neck glass, etc for rebuilding CRTs. Many gun assys and neck glass, bells, etc. for the old 21" color round CRT's. I am making arrangements for shipping.

    I know there are many people out there with rebuilding supplies that will help us in our endeavor.

  10. I just got a quote from my insurance agent for adding the rebuilding operation to the museum. Assuming we have one full time employee, the additional cost would be only $240 per year. The insurance company may require some things related to fireproofing the area, but I think that is prudent, since the last thing I'd like is a fire in the rebuilding operation that destroys some of our collection.