I have to agree with Alan. - Bronze balls did it for me (!!) for another reason... When I built my Brighton Terrier I made the crosshead pump and the hand pump with S/S balls - the hand pump fed through the crosshead pump. (I had read somewhere that this would enable you to force the crosshead pump inlet ball off its seat if it got stuck ) The fact of the matter was that in the VERY hard water area in which I lived (Portsmouth UK- water from chalk streams) the pump ALWAYS stuck. To try to solve the problem, when blowing down, I used to feed citric acid or vinegar into the water feed, all to no avail. Then I changed to bronze balls and - the problem disappeared. So Vivre Bronze Balls! Dennis MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.