Hope someone can give some advice here...I'm fairly new to quilting...The quilted thread is breaking and coming undone in spots on the first quilt I made ( I use nightly)...
I used coats and clark cotton 30 wt thread in bobbin and top, piecing and quilting it...If it's tugged the slightest bit (casual twisting and turning in sleep) it breaks...

Is this because I didn't use polyester thread on the quilting ( I read to use this when quilting somewhere)?..Not the right weight?..Anyone have a clue?

Unfortunately Coats and Clarks no longer seems to be the top quality thread that it used to be. I prefer to use Guttermans or one of the other "better" quilting threads on things that will get lots of use and wear.

poly threads do hold up better. cotton wears out, gets weak and breaks alot. you can re=quilt it if needed. 30 wt is actually a pretty heavy thread; we mostly use 40 wt threads for piecing i've used 50 wt and 100 wt too. the smaller the number the 'thicker' the thread...so your 30 wt thread is almost twice as thick as my 50 wt. also, if you use cotton thread i 'think' it will hold up better if the item is washed in cold water on gentle..

I use Sulky thread or guttermans

Did your thread have some age on it to begin with? And even if you'd just bought it, depending on the store you got it from it might have been sitting for a long time. Thread, even on the spool, will deteriorate over time. Unwind about 18 inches and pull on it. If it breaks without some strong effort, don't use it. You didn't mention what type of fabric you used for your quilt, if the fabric has any stretch to it the quilting thread will break---Tshirt quilts without the right stabilizer, Polar fleece, any knit fabric, etc. With those you just about have to use some type of stretch stitch even if it's just a zigzag.

So glad I asked this question. I've alread learned several new things from your answers...I did use top of the line cotton material on "that quilt" as well as freshly bought thread.. However, the many different types of thread weights/brands etc was enough to boggle the mind lol..I have since been using gutermanns and am really liking it..I plan on picking some up from ConnectingThreads as well. Sure helps to know what thread weight to get(smile)
And I had no idea about using the zigzag stitch when using fleece etc raptueready, ty...I have just finished 3 fleece covered pet pillow and plan on a fleece backed quilt for my sons gf next..
As soon as I make me another summer and winter quilt...I'll move my first and more fragile quilt to the occassionaly used pile..

Question:: I do have one more curiosity question... If the poly thread is so much more durable..Why would you not use that for peicing as well?..Oh, and is the thread weight rule( 40 and or higher) the same for poly thread?..Thanks so much from me and other newbie-ish quilters you guys. Great info

Okay, my own preference here---I only use cotton thread on vintage quilts or quilts I want to look vintage. For all others I use poly. But then again, I don't make show quilts, I only try to make my quilts durable because I want them used.

As with everything else in our quilting world, there are no quilt police and it is personal preference. I only use cotton in piecing and quilting with an occasional rayon embroidery thread for quilting. I also find that if the tension is to tight top or bottom that the thread will break when pulled. Also with any of the stretch type materials you need to have a 'give' in the thread. This is where the new machines have it over the older ones---they have built in stitches to use on these fabrics. The straight stitch that is built in for stretch machines goes forward 2 stitches, back one, forward 2, etc which makes the stitching stronger and able to stretch instead of snap.

Also, your question on using poly for piecing--I think it may have to do with the weight, but like I said above, I don't use it when making quilts so am not sure.

Excellent point about the tension Coyote.. I do know how to check my bobbin tension...When I took my machine to the viking dealer he set my top thread tention at 4...I figured he must know what he's doing..Although, I could be wrong about that lol

I too have had cotton threads "snap" in a quilt. My heart sinks. My teenager doesn't take care of her stuff. :(
I may try to "re-quilt" some areas of it.
I am going to try some poly thread in my next quilt for the quilting. May try Connecting Threads for it.

hmmmm Man, I hope my recently found longarmer uses poly to quilt with lol

I'm not sure about machine quilting, but in hand quilting if you dont stretch the quilt well while quilting the threads will break when you use it because when you pull the quilt over you it stretches the fabric more than the thread can and breaks the quilting threads. hope this makes sense

I use cotton thread for pretty much everything. But I do use the Maxi Lock once in awhile (its poly) My 2 cents: when quilting use a longer stitch length and a little looser tension on the top works for me BUT each quilt is different and each of us is different. Oh and I never use C & C thread.

Coats & Clark thread is made with short-staple fibers. Long-staple threads, such as King Tut, are stronger because there are fewer places for them to break.

Also, I am wondering how far apart your quilting lines are. Quilted lines 8 inches apart will be under a lot more stress when someone sits on the quilt than quilted lines 2 inches apart.

The "coming undone" problem may be related to how you fastened your ends. If you did not knot and bury ends, or stitch in place for a couple of stitches, or make tiny stitches at beginning or end of your line, this would allow the thread to come loose.

Although you can use heavier weight yarns for quilting (such as 30wt), it's more common to use 40wt or even 50wt.

Cotton thread doesn't have the stretch that poly thread does, so tugging/pulling on a quilt, agitating in the washer can cause threads to break too.

I use primarily cotton thread in all of my work and I have not had anything break - and the quilts have been through the wringer.

Do you still have some of the thread so you could do a tug test? You should not be able to tear off a piece of the 30-weight, at least not easily. I suspect that your quilt stitches might have been too small and that the tension was off.

Can you requilt it? If you don't want to see the second set of stitches, simply use a good quality polyester (NOT Nylon!!!) thread.

If you have long runs of threads against the bias, there is nothing that the thread can do but break, no matter what thread you use. I've also seen seams split when there is very little quilting on the quilt, and the seams have to take all the stress.

No, the popping/breaking usually occurs in the middle of a line..Not on one of the ends ( that might not be locked down good)....And my quilted lines are spaced around 3 inches apart...
I honestly think it's a combo of the cheaper thread (and not poly)and not a looser tention... What's the typical tention setting when quilting that you guys use?..As I said, the guy set mine at 4

You need to adjust your top tension to suit the specific thread you are using. 4 on one machine could be 5 on another, so that setting doesn't mean much. What is important is that the tension be set on your machine to suit the thread you are using.

You can check tension by examining some stitches to see if you have a balanced stitch -- bobbin thread should not show on top (or only be tiny dots) and top thread should not show on bottom (or only be tiny dots). Basically you want the interlocking of the top and bottom threads to be exactly in the middle of your fabric thicknesses.

If the top tension had been set too high, your thread would have probably broken while sewing. It doesn't explain why the thread is breaking after it is in the quilt.