Item number 163217794445 (Mcculloch Mc-93 Kart Engine) on ebay says in the description that several "low places" in the cylinder bore were brazed. Has anyone ever tried this. It sounds like a formula for disaster, but I don't know anyone who gave this a chance.
(08-31-2018, 07:42 PM)Blaine Young Wrote: [ -> ]Item number 163217794445 (Mcculloch Mc-93 Kart Engine) on ebay says in the description that several "low places" in the cylinder bore were brazed. Has anyone ever tried this. It sounds like a formula for disaster, but I don't know anyone who gave this a chance.
it's a very common repair when needles get loose and create grooves up the bore. Many different fillers have been used such as silver solder, silicon bronze, mild steel and even epoxy. Welding up grooves in cast iron with something like mild steel or cast iron rod is very hard to get right as it requires the base metal to melt. Using silicon bronze or silver solder only requires bringing the base metal up to red hot but not melting so it works better once you get to the re-bore phase. Not many people around these days that have the skill set to do the repairs. I've run several blocks that have been repaired and they run fine.
Steve O'Hara
on that note.
i read this post and was reminded of a terrible idea i have yet to try.
stay brite silver solder used for plumbing applications flows/melts at 535 degrees f
it's solid to flow threshold is 430 degrees F but it doesn't really move till 535 degrees..
stay brite is actually silver solder just a very low flow silver temp solder.
i think it would be safe for repair as it would wear easier than the cast it's embedded in anyway.
besides it should never get to melt temps since most two strokes don't do well at 430 degrees F .
so in my twisted mind it would be unlikely that properly applied stay brite would present any issues for needle repairs.
before i try this little operation does anyone have thoughts or experience will lower temp repairs like this??
pull sheet for solder.
CStay Brite® 8
Description: Stay Brite® 8 Lead-free Silver Solder
Both Stay Brite® and Stay Brite® 8 produce an overall component with greater strength than a brazed component whose base metals are weakened by annealment from high brazing heat. Stay Brite® solders bond with all of the ferrous and nonferrous alloys. Joints soldered with Stay Brite® solders exhibit considerably higher than necessary elongation for sound, dissimilar metal joints and vibration
d
Brazing can be pretty tough stuff. Frank Weir in N. Ireland, puts frames together with braze. My old TIG genius, Vince Stellman in Racine, WI, used to furnace braze broken pieces of classic tractor engine blocks together. They held fine, and the old tractors could be used again. Just try buying a block for a 1929 Hart Parr! TJ
(08-31-2018, 10:58 PM)David Luciani Wrote: [ -> ]on that note.
i read this post and was reminded of a terrible idea i have yet to try.
stay brite silver solder used for plumbing applications flows/melts at 535 degrees f
it's solid to flow threshold is 430 degrees F but it doesn't really move till 535 degrees..
stay brite is actually silver solder just a very low flow silver temp solder.
i think it would be safe for repair as it would wear easier than the cast it's embedded in anyway.
besides it should never get to melt temps since most two strokes don't do well at 430 degrees F .
so in my twisted mind it would be unlikely that properly applied stay brite would present any issues for needle repairs.
before i try this little operation does anyone have thoughts or experience will lower temp repairs like this??
pull sheet for solder.
CStay Brite® 8
Description: Stay Brite® 8 Lead-free Silver Solder
Both Stay Brite® and Stay Brite® 8 produce an overall component with greater strength than a brazed component whose base metals are weakened by annealment from high brazing heat. Stay Brite® solders bond with all of the ferrous and nonferrous alloys. Joints soldered with Stay Brite® solders exhibit considerably higher than necessary elongation for sound, dissimilar metal joints and vibration
d
Never tried it Dave but would be interested to know if it works. Keep us posted please. I know nobody will believe this but I used JB Weld once and it stayed in a Mac 49.
there's a builder who i can't name without permission who uses epoxy with good success.
i already have the stay brite 8 on hand as materials part of a copper still project i've been building.
sometime soon i'll try this idea then.
d