The Home Machinist!

careful about stretching the copper too far. It thins as you do this and you can end up with another level of problem.

before you do this in the boiler, suggest you try it on a dummy hole or two.

Don : Your real problem is still the holes are too big. .020 is too much to expand into. Too much clearance, too far to expand and get a tight seal. Yes the rough surface will help but you are removing more steel and making the hole larger.
Your neighbor, Alan

Do you anneal your tubes before trying to roll/swage them? I have heard a lot of people say that you don't really need to anneal the tube ends, but I always do that when rolling in the tubes. Heat about 1" of each end to an orange/red color and then quench in water. You'll see some scale come off of them when you do. I then rub them with some scotch brite to remove any of that scale that is left, and put them in.

Marty_Knox wrote:The problem could be the holes, not the tubes. For an effective seal the hole needs to be round, but not smooth. You want a slightly rough surface so the tube will grip. I have found the best preparation is to ream the holes after welding. I ream the holes dry, without any cutting oil. You do need to clean the swarf off after each hole.

Hi Marty,

How far oversized do you ream the holes. Right now i have a fully welded boiler with 0.875" holes and 0.875" tubes. What size reamer would you go with and how rough should the finish be on the holes after reaming? My first experiments hand reaming are showing that I definitely am not getting the best finish in my holes to begin with.

apm wrote:

Marty_Knox wrote:The problem could be the holes, not the tubes. For an effective seal the hole needs to be round, but not smooth. You want a slightly rough surface so the tube will grip. I have found the best preparation is to ream the holes after welding. I ream the holes dry, without any cutting oil. You do need to clean the swarf off after each hole.

Hi Marty,

How far oversized do you ream the holes. Right now i have a fully welded boiler with 0.875" holes and 0.875" tubes. What size reamer would you go with and how rough should the finish be on the holes after reaming? My first experiments hand reaming are showing that I definitely am not getting the best finish in my holes to begin with.

I go about .010" larger in the front tube sheet, and ream the rear tube sheet to size. You want the tubes to slide through the front tube sheet and be a wring fit in the rear.

I have plans for a tube roller designed by John Bailie if you need/want to make one. You can adjust the size to whatever you need. I made one and it works great.

Greg, How/where does one get those roller plans? I have a project coming up and can see the need in the future. (hopefully not to distant).

Jesse Livingston also published a design for a flue roller that has a threaded end on it so that it can be hooked up and driven through the tube from the front of the boiler, thus it can roll tubes in really small fireboxes. It's in his book 'The Shop Wisdom Of Jesse Livingston'. It was also published in 'Live Steam' several years ago.

Found the book on Amazon... $42.00 EESH! Might pay it if I know the plans are for the right tool. Having a slow time searching Live steam. I am hoping it is a true roller and not the swage type. I've heard that there is one out there that actually has rollers on it. I'm not a good machinist, but that would be a good tool to make, use and share.

Send me a PM with email address and I'll send you several designs that I have.

The plans are for a roller style tool. I made one and it worked great. Send me your email and I'll forward the drawings on to you. gregl@mail.fresnostate.edu

little giant wrote:Here is my plan of attack:
1) Remove all tubes
2) Ream holes to roughen up surface
3) Buy .065 walled copper tube
4) Swage the ends to fit closer to hole diameter
5) Roll tubes in
6) Report outcome

Thanks to everyone who helped me out

Did you ever report the outcome? If so, I missed the report. Were you able to fix the issues?

Thank you,

Jeff Smith
Florida