I have a Singer 4832 c. I can't find my manual. The top of the stitching looks great but the underside is creating large loops of thread.

Looping stitches can be caused by a few different factors. Make sure that your machine is threaded correctly. If the top thread or bobbin thread is improperly threaded it can cause looping stitches. ... Loose thread tension will create loose loops of thread that can cause the needle to catch and create more of a mess.
https://www.madeirausa.com/services/troubleshooting/fabric-puckering/

Did you happen to reload your bobbin and then it started shortly there after?

Maybe try a different fabric, thread, and bobbin, just to test the machine.

Are you saying the upper thread is knotting under the fabric as it stitches? This is bird nesting or thread nesting and is generally caused by mis-threading, the thread not being seated in the tension disk, or the upper tension too loose.

When threading the upper thread, ALWAYS RAISE the presser foot. Verify that the machine is threaded correctly. If one guide is missed, the stitching will go haywire. Start out with the upper tension set around the midway point and then tweak it through test stitching.

What causes Bird Nests Superior Threads

Sewing Machine Thread Bunching Up Here Why

Birds nest under the fabric big loops of thread top side looks good...

...

What kind of thread are you using. The most often problem today is that the thread is too thick for the size of needle. Try using a Metallica size 90 or a top stitching needle size 90
if the thread is a cotton type or a quilting thread it is often to thick to travel easily through the eye of a needle quickly to form a good stitch.

try adjusting the top thread tension to one number higher at a time until the stitches start looking right

also check with singer customer service for a instruction manual

Firstly check the tension on your bobbin case is sufficient or if the thread is actually into the spring fully, this is most likely cause of bottom thread loose stitching. You can test bobbin case tension adjustment using the "Dangle" test, here is a link to some good images to help.
http://www.sewusa.com/Sewing_Machine_Repair/Thread_Tension_Settings.htm

If you look closely and there is actually looping on the underside then is is the top thread coming to the underside and not being tensioned back up; so top thread is not under tension enough or at all.

Set top tension to 4-5, then recheck the threading up and and always thread with the presser foot raised as this opens up the tension device so the thread can seat in fully. Once you've threaded to just before the needle thread guide, lower the presser foot and pull the thread downwards, it should be very firm if its under tension.

Tension devices can get gunked up or fail with use so if you can't get it to feel firm, it will need a technican to investigate further.

It sounds crazy but if you have loops on the underside of your fabric it means your upper thread is not properly threaded (and vice versa for loops on the top of your fabric). So re-thread your top thread, change to a new needle if you've been sewing with it for a months and you should be good to go. Let me know if you need any more help.

Hi Lou! This sounds like a tension problem--the tension on the top thread is too loose. Try using different color threads on the top and bobbin, then carefully rethread everything. Stitch a couple of inches and check the underside. If the top stitches look fine and the bottom ones are loose and loopy, and with the pressure foot down, tighten the tension. Move the knob or dial (whichever you have) just a little bit. Sew a couple of inches more, and recheck. Continue to sew and recheck, gradually tightening the tension, until you see little if any bobbin thread on the top or top thread on the underside of the fabric.

Let me know if this helps, ok?


Robbie

This is a tension adjustment problem. It's good to use two different colors of thread, like you did. From your description, the top thread (needle thread) tension needs to be tighter. As you tighten the tension of the top thread, you'll see that the top thread pulls the bobbin thread up into the fabric so it's no longer laying loose on the bottom of the fabric.

You'll need to have the pressure foot down when you tighten the tension. Tighten it a little, sew a practice seam, check to see what the stitch looks like. Tighten it a little more, sew, check, etc etc--until both top and bottom look the same--you shouldn't see much (if any) of the bobbin thread color on top of the fabric or the top thread color on the underside.

Let me know how this works for you, ok?


Robbie

Try oiling the hook if you haven't recently.
Check you needle plate and hook for damage, they may need to be buffed or sanded smooth.
Check your upper tension discs for lint and double check your upper thread path (proper threading).
There are other things like hook timing, needle clearance or broken check spring that may be wrong but you need a technician for those things.
best of luck!