Top Thread keeps fraying on dacron

[Josacraw]

Hello I know this outside of the forums leather scope but since it involves thick fabric and an industrial machine I was hoping you guys might have some advice.

I'm sewing through 7 to 8  of 9 oz dacron sail cloth with 92 thread and 22 gauge needles of the SD1 variety. The machine does fine when i get under 5 layers but thicker than that my top thread keeps fraying. Should I be using a larger needle? Or should I try something else.

 

The machine is a consew 255B

 

Thanks

[kgg]

24 minutes ago, Josacraw said:

I'm sewing through 7 to 8  of 9 oz dacron sail cloth with 92 thread and 22 gauge needles of the SD1 variety.

What kind of machine?

kgg

[Josacraw]

4 minutes ago, kgg said:

What kind of machine?

kgg

I thought i said in the post consew 255b. Thanks

[trash treasure]

If you're using a decent bonded thread, then a #22 should normally be OK with V92, but maybe on that heavy of a stack, I might try  a 23 - Can't hurt to try.

But I'm also thinking you have a burr somewhere - Maybe in the foot needle hole, or the plate, or the hook.   I grind them out with a dremel tool and diamond burrs, and finish polish with one of those little rubberized abrasive points.  We use mostly Organ Titanium needles for sail work - They seem to have a little less of a problem with seam-stick tape, but that's a different subject :~)

[kgg]

16 hours ago, Josacraw said:

I thought i said in the post consew 255b. Thanks

Sorry I missed that. I would check for a burr like trash treasure suggested. First I would start with the simply change of the needle.

Who's needles are you using?

When I sew 1000d ripstop I find that I have to change the needle more often as it seems to dull the tip quicker. I find if I use bonded polyester thread rather then bonded nylon it can have a tendency to occasionally fray as the polyester is a little softer particularly when doing a 90 degree turn. I figure it's when I bury the needle and physically turn the material. I figure the material must be slightly catching / deforming /scratching the thread.

What type of thread are you using and who makes it?

kgg

[Wizcrafts]

I dunno the standards for needle/thread combos in the sail sewing field, but in the leather end we usually use a #19 or possibly #20 needle maximum with #92 bonded thread. It seems to me that a #22 needle is poking too big of a hole and the tip can't slide past the thread knots as easily.

I occasionally sew non-leather items in my shop. Of course that calls for round point needles. Lately, I have been buying Groz-Beckert Gebedur needles and they are fantastic. Gebedur needles are titanium coated, but last longer under stress than the Orange brand.

You might try dinking with the check spring slider position. Normal operation has the screw in the middle of a curved slot. Turning the disks clockwise tightens the top thread by reducing the slack on the downstroke. Try doing that. Loosen the little screw in the curved slot, back off the round nut and turn the disks clockwise, then lock them back down. If it gets better, problem solved. If not, return the screw to the middle, or try turning it ccw for more slack.

Note: tightening the check spring slack setting all the way may cause the top thread to snap as it goes around the shuttle. If this happens, back off a tad.