Hello everyone,

After going thru several old steel tube boilers in the past decade it was finally decided that the Auburn Heights 725 would be given a copper tube boiler. I have been told it is a trial to see if it is practical to have a copper tube over a steel tube boiler in a condenser.

I myself was not at the meeting where the decision was made. I don't know if it related to cost and availability or if other reasons were considered.

Although it may be added in the future, it was decided not to add an oil separator. Instead a sock used to soak up oil was inserted into the tank in the area of water pump inlet. A standpipe was also added to the boiler to help blow any oil that gets into boiler blown out when blowing down.

After driving and riding in the 725 on several occasions, its performance has substantially improved. I have spent many years in the past riding in the car on tours and am aware of the performance of the car with a steel tube boiler.

I was first convinced the car performed better when the car was climbing a hill at 25mph with 5 people in the car for a lesson and the car held pressure at 550lbs with a cold belly tank.

The car also starts more quickly.

It seems most of the performance difference between the later non-condensers and the condenser cars is the boiler tube material.

For whatever reason it never occurred to me that since copper has a conductivity that is much higher than steel that the copper boiler would have made a huge performance difference.

If it gets to be lots of climbing I'm sure the condenser will still slow down a bit more, but the later cars are more comfortable for touring and although the roads I have driven on are not straight enough to allow speeds much faster then 30. I'm sure the car will probably cruise a 40-45 opposed to 30-40.

I'm actually excited for the next opportunity to take it on tour.

It has changed my opinion of the condensers and now I feel I would be more inclined to consider ownership of a condenser stanley someday.

Has anyone else noticed this difference?

Regards,
Robert Hopkins

David Nergaard has written on this,,,,used plastic pot scrubbers in separator,,
No oil in tank,,,,barely discernable color on tank overflow,,,
Jerry Hackett has found a synthetic oil to eliminate all the oil problems,,,
AND no need for a separator,,!!,,
Both of these have been written up,,,,,somewhere,,
Rolly,,,,can you elaborate,,,
If the tubes are restricting heat flow,,,the temp in the smokebox will be elevated,,???,,
Fuel mileage go down,,,??
Cheers,,Ben

Thanks for the response Ben.

On saturday, we had a 40 mile tour as an end of the year short tour at Auburn Heights and I measured a gas temperature difference around 50F between a copper and steel tube. With the steel tube being the hotter. That was them both around 400 psi. The exhaust gas temperature will vary with the pressure as boiling temperature of water increases with pressure.

Well they both have similar firing rates, but I'd imagine the copper boiler would give better fuel economy since it is more efficiently absorbing heat. If the burner is on full the fuel economies would be similar, but you'd have more steam available with a copper boiler.

So a 20hp condenser and non-condenser have the same burner rating, but the non-condenser would have a higher steaming rate and thus more available power.

Robert