Does your ring stretcher mark the inside of your rings?

Hi - decided to invest in a ring stretcher back in February and having waited a couple of months for Cookies to get them back in stock it finally arrived mid May.

Works great for stretching BUT noticed with the first ring I re-sized that I had marks on the inside, which I thought I had filed/sanded before putting on the ring stretcher, but decided that I couldn't have, so refiled and sanded. No big problem but was annoyed with myself.

Second ring resized - same issue - and I definitely made sure the inside of the ring was smooth first.

On checking the ring stretcher spines, they seemed a little bit sharp on the edges especially when opened up, so thinking this was the cause of the marks I sanded them with smoother with emery paper.

Next ring I did was a little better but still marking.

I have reported the issue to Cookson with photos, and they have referred the issue to Durston but two weeks later they haven't had a response (although to be fair there's been a bank holiday in-between).

So just wondering whether significant clean-up is to be expected after stretching. The attached photo is of a test ring I did, 1.85mm sterling, rounded with rawhide mallet after soldering, inside sanded smooth. Then put on the ring stretcher and increased by one size. I used platinol on the inside of the ring just to highlight the marks I am getting - they are quite deep and will need filing to remove.

Attachment 9012

Thoughts? Is my ring stretcher faulty or are the marks to be expected?

Thanks, Susie

Hi Susie,
If it's the Durston one, I've had some light marks, but only where I haven't turned the ring enough, and been too vigorous with each pull down. Tiny increments and regular turning will help.
Lydia

I've not managed to do that with mine. I shall go and try and see if I can replicate it later.

I think it inevitable that the inside of a ring will be marked with shiny facets by stretching it on a metal mandrel.

Normally the effect is very superficial and the inside of a ring is the easiest part to polish with rotary tools. So I just leave the final finish til after stretching.

That said, the severe indents in your picture are unacceptable and eradicating them would significantly enlarge the size. I should ask for a refund and get another make entirely. Dennis.

Quote:

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Originally Posted by susieq

On checking the ring stretcher spines, they seemed a little bit sharp on the edges especially when opened up, so thinking this was the cause of the marks I sanded them with smoother with emery paper

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Those marks look fairly brutal. Can you show us a picture of the ring stretcher giving a close-up of the splines? They're perhaps not quite as they were originally if you've taken emery paper to them.

Thanks for the replies - unfortunately I have tried to get decent photo of the ring stretcher splines but been unable to get anything in even reasonable focus. I wonder if I could get a decent closeup through a magnifying glass? Will search it out. The emery only took off the very sharp edges, in much the same way I run emery along the edges of new pliers and the marks before I did this were worse.

None of the pulls on the handle of the ring stretcher were harsh - in fact it's not yet properly anchored down so I have been very careful and gentle when I've been using it.

Hopefully Durston will get back to Cookies soon. I do wonder if the reason their ring stretchers have been out of stock for a few months is because Durston have either changed the maker, or have had quality issues?

I am not at the studio until next week but will give it a go and see if I can take a few pics

Thats definitely not normal.
I stretch mine before finishing so there may be very slight marks but nothing like that.

OK, I've been able to test mine; I *can* get some fairly deep marks into a ring - but only through going to the full extent of handle travel, which isn't how I normally use it. I usually stretch it a little bit (not even going halfway on the handle), test, flip it over & continue.
My 22mm bit of copper pipe used as a test is now up at 26mm.