I am having an issue with the top wrap over an under wrap getting gaps in it. The under wrap is tight but I can't get the gaps out of the outer wrap. Help please?

Are you using the same size thread for both wraps? If so, try using a size larger for the overwrap. Also, you can try running the overwrap in the opposite direction as the underwrap (ie. start at the guide ring and wrap towards the foot).

Jay is right that's old school. I also used to scratch the finish with scotchbrite on the underwrap it seem to help a little with getting the guide wrap to stay where you put it. It is however a skill that takes some time to master. Once you get some practice in with it you will be all the better even at any thread work. Keep practicing it and don't be afraid to tear and redo as its one area that will pay off for the perfectionist in the long run.

Hello Chuck.

Another thing you can do is to epoxy the under-wrap then when it is dry(10-20 Hours depending on temp and mix) put the second wrap on, epoxy that thinly lastly a top coat of epoxy.


Tight Wraps.

Bob,

New Bern, NC.

I forgot about putting epoxy on the under wrap, I will also try the way of reversing direction. Thanks for the info.

Edit: Read the question wrong. Thought this was a crosswrap underwrap.
Sorry for confusion.



Edited 1 time(s). Last edit at 12/09/2013 01:25PM by Adam Curtis.

There are a number of things that can help.

Wrapping the underwrap in a direction of guide ring to guide foot spirals the thread one way, and then wrapping the overwrap from guide foot to ring spirals it in a different direction. In this way the overwrap thread is less likely to follow the lay of the underwrap.

Pack the underwrap threads tightly, and then burnish the surface. Packing reduces space between threads and burnishing flattens threads. Both steps help reduce the size of the valley between threads that allows overwraps to get trapped in the valleys and show as gaps.

Excessive overwrap thread tension will pull a thread down into the valley between underwrap threads, so as some people have mentioned above, a coat of CP or finish can fill those valleys but I'd try a little less overwrap tension first.

With proper thread tension, and packing and burnishing of the underwrap, you should be able to adjust and close gaps in an overwrap without having to resort to increasing overwrap thread size.

I'm sure some people will disagree with me on this, but when the underwrap is properly laid and prepped, there should be little or no need for CP, finish, or larger overwrap thread.

John, you are correct. I regularly use A on underwraps and overwraps with no finish in between...I have even triple wrapped with all A with no problems.

But the OP asked the question, and we are beholden to give the best answers we can.

Properly done, none of the above is necessary.