Would Appreciate Your Advise On Restoring This Singer 45K25

[Evo160K]

Hi Constabulary,

Project is moving slowly but surely forward. I have most of the majors parts thanks to some great people here on LW. Haven't tried the decals yet. Plan is to get the machine sewing well, which for the most part it is, then pull it apart for cleaning and painting. Do you have any parts that I can use on the 45K25?

Have a small issue that I'm trying to solve. The machine sews well with all threads except a high temperature fiberglass that we used to use in our business. It's about a 138 with a tensile strength of 12 pounds. Issue is it sews for a couple of stitches, sometimes just one, then breaks the top thread, looks like the thread has been hacked partially through multiple times with a dull knife. It will sew fine without material, but not with material (leather). I can't figure out where it's being hacked. I looked and polished every part I can get to, the tensions seem fine and the automatic thread controller loosens the thread just before it enters the leather.....it's a mystery. I've asked one of the sewing machine mechanics at a large, local, sewing manufacturing operation to stop by for a look.

The listing you put on eBay for the Singer 105-6 was outstanding, you do have a talent for it.

I don't need the 29K71 but I will buy it if the freight isn't too high, it's about 1,000 miles from me.

Best regards

[Frankqv]

Try going up one needle size.

[Constabulary]

I think I have no parts you would need. Didn´t get new parts.

I never have sewn with fiberglass thread but when the top thread breaks and the machine is threaded correctly then try a new needle or a needle 1 size larger. I´d also try to loosen the top and bottom tension a little bit. Do you wrap the thread around the tension pulley (the one before the thread regulator spring) 1/2 or 1 + 1/2 times? How old is the fiber glass thread? Is it probably "too old" to sew with it? I don´t know this type of thread so I honestly don´t know how and if it is aging.

I really wanted to keep the 105 but I got it at about the same time as the BUSMC 6HM (this really was a lucky circumstance and I had to act fast) and I had to decide which one has to go. The BUSMC has much more punch and can sew much thicker + it has a needle feed (was great for the heavy tent repair) and I love vintage machines. So it was the 105 that had to go. It was also a question of $$ (glad it sold fast). The BUSMC is cool but I think a Singer 97 would suit better in my "sewing room". So in case I will find one I´d probably sell the BUSMC again. But I´ll restore it first and then.... well, I don´t know... I think I can´t let it go... too cool machine

The 29K71 in NYC is a bargain and in nice condition too but sipping will probably cost a lot.

[hyttogpine]

I'm once again fascinating by all your skills and knowledge. Amazing.

The ability to a Singer 45K25 machine, compare to a Singer 29-4. If we say a 29-4 is meant to light leather swing. Will a 45K25 be for light to medium or maybe medium leather sawing ?

[Evo160K]

Frankqv, Constabulary,

Thank you, I will try a larger needle.

Constabulary,

I do wrap the thread 1-1/2 times around the moving pulley wheel. Jimi set me straight on that. Thanks for mentioning it. I'll also ease both tensions a bit, but one at a time. Recently. I tested the fiberglass thread's strength with a fishing scale to a breaking strength of 12 pounds, that's close to a 92 thread and should easily handle an 8 ounce veg tanned leather. The way the thread is being chopped up in so many places, I don't think the thread is at fault.

hyttogpine,

Amazing is a good choice of words. Constabulary and many other experienced sewers on LW are a wealth of knowledge and experience, plus they're willing to help---great people. I wouldn't even attempt a restoration with out them.

I don't know enough about the 29-4 to answer your question. Others will need to jump in.

[Darren Brosowski]

Try running it with the needle bar a touch lower

[Frankqv]

Frankqv, Constabulary,Thank you, I will try a larger needle.Constabulary,I do wrap the thread 1-1/2 times around the moving pulley wheel. Jimi set me straight on that. Thanks for mentioning it. I'll also ease both tensions a bit, but one at a time. Recently. I tested the fiberglass thread's strength with a fishing scale to a breaking strength of 12 pounds, that's close to a 92 thread and should easily handle an 8 ounce veg tanned leather. The way the thread is being chopped up in so many places, I don't think the thread is at fault.hyttogpine,Amazing is a good choice of words. Constabulary and many other experienced sewers on LW are a wealth of knowledge and experience, plus they're willing to help---great people. I wouldn't even attempt a restoration with out them.I don't know enough about the 29-4 to answer your question. Others will need to jump in.

It's not the breaking strength of the thread,it's the thread diameter,the coefficient of friction going through the needle,

[Evo160K]

Thanks Frank,

The thread has a diameter of .015" (.39 mm). The thread has been breaking with 19 through 23 needles in 8 oz.. With a 24 needle, it sewed fine in 8 oz veg, but broke in 12 oz. With a 26 needle it sewed perfectly in both the 8 oz and 12 oz. What does that tell us?

Thanks Darren,

I will lower the needle bar a touch. What's your thinking there?

[Darren Brosowski]

Just a bit more free thread below the work. May not make a difference.

Depending on the behaviour of the thread raising the needle bar a touch may help

[SARK9]

With some of the material you need to sew in the machine, try to watch the loop being formed on the upstroke and see if the thread's behavior and its relationship to the hook suggests a possible cause for the "chopping" effect. It *sounds* a bit like the hook is clipping a squirrelly loop caused by some odd flexing properties this stuff may have. You may have to adjust the machine's clearances to the extent that your machine becomes "dedicated" for use with that one thread type. I "hear" is a bear to sew with properly, but I've never tried it.

The shards and sheds from fiberglass and kevlar type threads are incredibly abrasive, and will find their way into everything.

-DC