First, let me state that I have absolutely NO credentials (as many of the other posters-- Matt Austin, J David, Dave, Tom Gears, Linn M., etc.--- do) in the steam biz. So, my questions/comments may be "naive".

The boiler interior coating product called "Apexior" has been available for over 70 years. I think some modern-day operators of steam locomotives have used it, and I wonder what beneficial effect it has on scale formation/retention, stress cracking, seam embrittlement, tube pitting, grooving, etc. It must be applied over a clean, sandblasted surface, so that may be difficult for some loco owners to achive. Has anyone had any long-term experience with this product and what it can do?

The second subject is lay-up of a locomotive boiler. ATSF practice "back in the day", as one example, was to fill the boiler through the dome and then add a few dozen gallons of diesel fuel to the water surface, then drain the boiler through the washout plugs. Obviously, the fuel oil went you-know-where, but the concept was for it to coat the interior surfaces and prevent corrosion during storage. I think soda ash was also tossed in when the boiler was drained and dry. I suppose the draining water/oil could be caught and separated.

Would filling the boiler with nitrogen, after draining and drying out, be useful/possible/affordable?

Just some random thoughts and questions from a dabbler here.

Howard P.

Never had occasion to use Apexior - all the old hogs I dealt with had nasty old boilers and highly unlikely any applied coating would have not experienced adhesion or consolidation problems in service. My career was spent in marginal underfunded startups mostly, so doing everything with nothing was SOP rather than going for top quality from day one. I know a lot of pretty smart people use Apexior, so i'm not at all unfavorably disposed to it despite my ignorance.

dave

Howard, I think I can hear your gears turning from here! I could be wrong.

Oh, strictly curiousity on my part.....

Howard P.

Apexior is great stuff for protecting surfaces that can be sandblasted to white metal and cleaned. Surface prep is everything. Use it for boiler shells and tender cisterns. ( I like Aquatapoxy better for water tanks, to each his own. )

What are you going to do in the firebox water legs ? Turn the boiler on end and slosh it with Phosphoric Acid, then neutralize it with Di Sodium Phosphate ? ( Tri Sodium Phosphate would go caustic upon drying, building destructive caustic corrosion cells into the crevices. ) That may work for an antique tractor gas tank, but not many shops have a manipulator to slosh their loco boiler.

Oh, yes there is that problem of heat transfer. Pennsy measured 2/3 of the heat being transferred in the firebox, 1/3 via the tubes. Why install insulation ( paint ) in your firebox water legs ?

Well, when replacing the firebox you could theoretically sandblast the whole boiler shell interior and apexior that before installing the new firebox. Might have to use threaded stays, however....welding temps might burn the apexior. That provides protection for the bulk of the boiler, without insulating the heat transfer surfaces of the firebox, which is a replacable commodity anyhow according to historic practice.

dave

Dear Howard:
I have used "Apexior" on most of the boilers that I have reubed over the last 40 years or so, including, I believe, your No. 1246, which Ted Wichmann and I did up at Bellows Falls ca. 1984. Take a look inside the boiler and look for brush marks. Generally, brush marks are still visible when you go to "do it all again"...
J.David

Dear Howrd; I certainly second Dave's report of the longevity of APEXIOR. At the behest of Dick Stone in 1977, we applied it to the interior of the NKP 765 boiler and it was still there in 1986 when we retubed her. We sandbalsted, reinspected and repainted with APEXIOR and it was still in there when we retubed her in 2005. I saw the brush strokes when we opened up the CB&Q 4960 in 1982. She was painted in the 1950's. Bob Yuill saw the brush strokes in the N&W Y-6b's that were scrapped in Roanoke in the late 1970's and they were painted in the 1950's. APEXIOR ( properly applied) prevents boiler water from ever touching the steel of the boiler shell. The shell being accessible and very expensive to repair should be protected by APEXIOR. Firebox sheets are cheaper to repair and the insulation concern is valid. We have tried to heat steel painted with APEXIOR and have seen a great resisitance. I have painted APEXIOR in every locomotive boiler we have restored, retubed and repaired for the past 33 years.