Marks Holt 75

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After cooling the part was returned to the lathe to face off the flange. And then I sanded the surfaces clean.




Jacket flange faced.jpg


Jacket flange done.jpg
 
And then the flanges were sanded smooth and parted off one by one. The small fanged ports were soldered to the jacket with solder paste. Wite Out was used again to control the solder.


small flange sanded.jpg
small flange whiteout.jpg
 
After soldering, the flanges were drilled through the jacket wall and the holes for mounting hardware were drilled and taped. And then the flanges were faced. The final step was cleaning the parts and treating with a gun browning solution. Now that gives the jackets a nice sweaty look. I plan to age all the cast iron and brass parts on this model.


small flange faced.jpg
jackets browed.jpg


I think they look nice, but we all have different tastes. So now its time to cut some cylinder liners from cast iron. Thanks for watching

Mark T
 
Hi Mark;
Following along with the build and learning! Great work. What browning solution did you use ? How was it to work with? I like the look.
cheers Garry
 
What browning solution did you use ? How was it to work with? I like the look.

I used Birchwood Casey Plum Brown barrel finish. This is not the easiest to use. It is a hot browning solution. The part temp should be around 275 degrees and very very clean. It usually takes several applications to get the darkness you want. My jackets were sandblasted, polished metal will brown more evenly. And submerging the part in the solution is best but is rarely practical. I applied the solution with a cotton swab that I held with chop sticks to avoid burning my fingers. Keep applying the solution until the part has cooled. After browning let the part sit overnight before washing the solution off with hot soapy water and then burnish with a soft cloth. Then rub on some light oil mixed with a little lanolin.

Mark T
 
Thanks Mark! I know of that product but have no experience with it. You don't see it on the shelves in this neck of the woods so I never went any farther with it. Time to look harder!
Thanks again
Garry
 
After soldering, the flanges were drilled through the jacket wall and the holes for mounting hardware were drilled and taped. And then the flanges were faced. The final step was cleaning the parts and treating with a gun browning solution. Now that gives the jackets a nice sweaty look. I plan to age all the cast iron and brass parts on this model.


View attachment 113447 View attachment 113448

I think they look nice, but we all have different tastes. So now its time to cut some cylinder liners from cast iron. Thanks for watching

Mark T
Fantastic Work
 
The cylinder sleeves are made of cast iron. I started with a piece 1.25” by 12” and using my lathe I removed more that 95 percent of the material to find my sleeves. With a 1 inch bore and .063” wall the sleeves are fragile. The plan called for a press fit into the cylinder jacket but I chose to make them a slip fit and glued the sleeves to the jacket with loctite 680.


Material.jpg
 
I cut the OD on the lathe and drilled out the center to ¾ of an inch before parting off. The parts were then held in a collet chuck for cutting the bore to size. I used a tool with a bit of radius, at my slowest feed rate to cut the bore. The tooling marks are not deep but it will take some work to smooth the bore.




sleeve outer.jpg
sleeve bore.jpg
 
For the next steps I turned down a mandrel to a close slip fit for the cylinder assembly. Using the mandrel I cut a chamfer at the bottom end to ease installing the piston with rings. And then I reversed the part and faced the assembly.
sleeve mandrel.jpg
sleeve chamfer.jpg

sleeve face.jpg
 
To drill and tap for the head bolts I mounted the cylinders to the top half of the block to make it easy to mount on the mill. From there I gave the bores a preliminary honing with a ball type hone to take the sharp edge off the top of the cylinder and to smooth the chamfer at the bottom. I still need to hone the cylinders with a precision finish cylinder hone but I need new stones for my tool and I'm waiting for them to arrive.


Drill and Tap.jpg
 
On to the heads. I used the lathe to remove as much material as possible. Next I drilled the holes for the head bolts and roughed out the shape. The plans have the head bolts crowding the edge of the head. That bothered me so I am making the heads a tad bit larger.


rough cut.jpg
 

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