The Steamboating Forum

Hi steamboaters,
I sent this same question to the Yahoo steamboaters group, so sorry for any duplication.

I have a pinhole leak in a 1987 Semple VFT-40 vertical fire tube boiler, which was discovered during annual hydro pressure testing.

Photos of this are on the Yahho group site, and I'll see if I can post them here or on main web site tonight.

1) can a VFT tube be fixed, capped, etc?
20 Is it worth fixing this one tube, or is it possible to "scope" or test the boiler for future problems?
3) This boiler sits in a Beckmann Mase 22' steam launch that I am really considering selling to a full-time steam enthusiast (with or without the boiler problem); the boat is in great shape otherwise (engine, tandem trailer, topside, extra finishing touches, etc)

So, I am somewhat upset that a planned outing here in Chicagoland has gone sour, so any advice is greatly appreciated.
Doug Hitchcock
drhitch@comcast.net
585-704-3977

Some other details:
-- I hydro test the boiler annually by using the manual backup feedwater pump to about 200 psi for 30+ minutes
-- When I inspect the underside of the boiler tubes from within the firebox, I see that about 1/3 of the area of th botom plate has some minor rust, so this leak may actually have been there last year during some steaming periods.
-- Semple that made the boiler is out of business?
-- Can this boiler be removed from a boat that has a hardtop canopy? Likely would need to be tilted and "grunted" out of the boat by full rugby team?

1) can a VFT tube be fixed, capped, etc?

ANS: Yes, there are US Navy procedures to plug a leaking firetube if required, usually with a threaded rod, nuts, washers, and two rubber stoppers. The rubber stoppers are inserted into the tube, the nuts tightened on the threaded rod to expand the rubber against the tube ID, and there is your seal. I will look for the details in my “old engineering book” collection.

2) Is it worth fixing this one tube, or is it possible to "scope" or test the boiler for future problems?

ANS: Depends on the condition of the rest of the boiler, and the circumstances surrounding the sea trip. If you are out on the ocean, then definitely plug the tube right away, if you have weeks until your next outing, then conduct an inspection, etc.

You can UT (Ultrasonic Test) the tubes to see if there is a general problem with all the tubes. Heat Exchanger shops do this all the time, last test I reviewed was a UT report on a condenser that had 14,000 tubes, 40 feet long each.

Depending on the condition of the rest of the boiler, you may just fix (or plug) one tube, re-tube the entire boiler (about $1000 +/- ), or have a new boiler shell made (non-code, $3000 - $5000, or ASME Code $ 4000 - $8000)

3) This boiler sits in a Beckmann Mase 22' steam launch that I am really considering selling to a full-time steam enthusiast (with or without the boiler problem); the boat is in great shape otherwise (engine, tandem trailer, topside, extra finishing touches, etc)

A nice machine, but I don’t like those new-fangled twirly things they have been using to make boats go.

What is your operating pressure?

The flue sheets on either end of the Semple flues have machined recesses allowing the weld bead to lay almost flat on the sheet. Removing a flue involves first grinding off as much weld as reasonable on both sheets, then making a cutter which aligns inside the bad flue(s) to actually cut 3/16"+/- off the end of the flue and into that ditch...on both ends. The portion of the flue generally under water will be in much worse shape than the portion in steam and probably corroded enough that it will not easily slip out of whichever end sheet you decide to drive it.

Making a ram to drive the flue out will certainly mushroom the part just under the sheet side being driven so sliding it all the way out may not be possible. Also keep in mind driving the ram with a 12 lb sledge will distort the sheet so try to start in the middle using the remaining flues as a support structure holding the sheet in shape while whaling away.

When my Semple VFT 40 started to leak I chose to replace all 73 flues, and glad I did as those not leaking were in bad enough shape that they would be leaking soon.

After cutting the ditch and driving each flue back, we torched off the portion sticking out the "other end", then drove the cut face back into the boiler to remove the mushroomed stub end out through one of the 1 1/4" inspection/connection holes with coat hanger wire.

Quite a dirty and major job and if you have a certified welder do the job, expect a bill well over $3k...even if you help. Since you plan to sell your boat you've gotten yourself in a bad place, but I've talked to several new owners in the past couple years who've bought boats with leaking boilers, so maybe the solution is to just be a jerk and unload it to the next "city guy" who shows an interest.

Thank you for reminding me of something that should go on the list of things to do when buying a complete boat, and that would be "Insist on a hydro test in my presence, and preferably in the presence of an experienced steamboater as well."

At last year's NWSS annual meet at Cathlamet, right down the river from Portland, a fella arrived with his beautiful "new" boat ready for a weekend of fun. After the mandatory hydro showed several of his flues leaking the weekend became a real challenge between the NWSS board of directors who didn't want a dangerous boat steaming around at a "formal" club meet and the new owner over his demand that it was a public river and he could darn well steam wherever he wanted to. Tempers grew and some feelings were hurt over the impass...after all, he'd spent $22k on his "new" boat and wanted to run it.

Just goes to show "A fool and his money are soon parted"

What part of "boiler explosion" didn't he understand?

Try adding Rislone Head Gasket liquid seal to the water in the boiler through the whistle nipple. It stopped my leak and I hope it lasts.

I can see using the liquid if it is a leaking thread but if it's a pinhole caused by corrosion well,that might not be a good move! Den

When I was in the Netherlands in 2000 for "Dordt in Stoom" we rode on the Finland, a steam tug, from Rotterdam to Dordrecht. A few days before we were to set out the inspector arrived, and it was determined that a flue was leaking in the giant Scotch boiler. The boiler was still warm, but it was drained and a fellow wearing two boiler suits sent in via the combustion chamber. A set of plugs had been fashioned, and a large threaded rod w/ nuts was used to pull the plugs tightly into the leaking flue. Once the red-faced fellow was out again, the boiler was rehydro'd and we were back in business.

- Bart

When I was fireman on a 90 ton Shay geared logging locomotive some years ago, there were two times when flues were leaking enough at the firebox sheet to affect the fire. My status was low enough (the son of the engineer) that I was elected to deal with it.

Paying customers were being turned away so there was no time for cooling the boiler to ambient temperature. The boiler was brought down to zero pressure (100C), some planks were arranged in the bottom of the firebox to stand on and wearing a couple of pairs of coveralls, a baklava, heavy boots and gloves, I entered the firebox with hammer and punch.

These flues were rolled in place and then flanged over with an air hammer. My task was to use my forked punch and two kg hammer to further seat the rolled over flange and stop or slow the leak.

The trick was no not exert enough effort to need to breath deeply. 212F air is painful to inhale. Also, any areas of my clothing that got damp were painful. Dryness is the trick.

I took several breaks to exit, cool off and drink amazing quantities of water. My work was sound enough to last until the seasonal layoff when we could re-roll the offending flues with power tools in a cool firebox. I was much younger and agile too!

During W.W.II there was research done in heated chambers as to how hot humans could live for limited periods of time. The researchers were their own subjects. It was found that if the humidity was extremely low and the subjects avoided rapid air currents and wore loose clothing, that they could carry steaks into the chamber and have them cooked while they shared the space. Skin evaporation and respiratory fluid evaporation allowed survival at temperatures where meat was cooked.

Mild madness.

Mike