ShavingUniverse.com

Register a free account now!

If you are registered, you get access to the members only section, can participate in the buy & sell second hand forum and last but not least you can reserve your preferred username before someone else takes it.

Strop "cupping"

clovis

Well-Known Member
Hi everyone, I need some help with a paddle strop I have. Its from from a well known commercial maker and the leather side (other side is pasted balsa) is marked wild juchten. The problem is he leather has started "cupping" ie its not flat across the width of the strop and is higher at the edges than the middle. Is there a 'cure' for this?
 
Hi,

I am having a hard time visualizing your problem. What type of paddle is this? Could you post a picture of it? I could probably give some advice then.

regards,
Torolf
 
Not yet worked out how to attached photos but strop is a sprung paddle, leather one side, red pasted balsa on the other. There is a photo of the same make/type of strop here http://straightrazorplace.com/stropping/18177-dovo-paddle-strop.htm

Problem is the leather is no longer flat and has become 'U' shaped, If I was to try stropping the razor would only touch the leather at the edges but not in the middle. Rather like a gutter for collecting rain water. Sketches below may help explain.


_______________ Flat leather


\_____________/ 'Cupped' leather


Regards
 
Hi Clovis,

I have had a look around at sprung strops and all seem to have the leather adhered to the wooden base. If yours is cupping, I really don't know what is going on. Follow Wim's link and get a picture up.

All I can think is either your leather has separated from the wood, or the wood itself is warping...

regard,
Torolf
 
Thanks for the picture link - pics to follow! I terms of construction, the leather is fixed (nailed/stapled) to the wood at the ends, along its length it just rests on a felt strip so is free to curl - which is what is doing.
 
Thanks for the picture link - pics to follow! I terms of construction, the leather is fixed (nailed/stapled) to the wood at the ends, along its length it just rests on a felt strip so is free to curl - which is what is doing.
 
Here goes with the pics.....

First picture shows (I hope!) the strop with a 6" steel ruler across the width,
/home/kirstie/Desktop/cupped surface.jpg

Second picture shows the side of the strop and the felt the leather sits on.
/home/kirstie/Desktop/felt view.jpg

Thanks for all the help so far.
 
Here goes again with the images....

feltview-1.png

cuppedsurface-1.png
 
Hi Clovis,
Thanks for putting the pictures up. That is unfortunate (what is the width?).

There are several things I can say. If the leather is very supple, don't worry about it, just use more pressure. The design would accommodate that, but only if the leather is very soft.

You could try running your hand up and down the edges, cupping them back over. But I think this would not be a permanent solution.

What would be the most likely long term solution is this: Take some tepid water with a drop of dish washing soap in it (one drop in 500 ml maybe). Wet a sponge and wring it out well so it is just damp. Quickly and uniformly run this over the surface of the strop. Then wet/wring the sponge and do it again after a minute. The leather should have been clearly dampened, but not wet. Wrap some plastic wrap around the whole strop, bending the edges over. But make sure there are no wrinkles in the plastic, marks made on the leather will not come out later. Let it sit over night.

Take the plastic off and lightly form the edges over as you would like them (if needed). A little extra at this stage wouldn't be bad. Do this several times over the next few hours.

Put a little neatsfoot oil on your hands and rub it well into the whole surface of the leather (just a little oil). If this disappears immediately, do it once more. This will change the draw somewhat, but probably for the better.

Personally, I think your leather may be dry. But just oil alone at this point (without the wet forming) most likely won't solve the cupping.

Good luck with it, padded strops are very nice and a good piece of kit. Having the middle length of a padded strop higher than the edges is no problem.

regards,
Torolf

ps. Don't think you need to baby the leather, make it do what you want it to, but gentle is good. My concerns about the amount of water have to do with the fact that you do not want to get the foam wet.
 
Torlof,

Thanks for the advice, you're right, it is unfortunate. The leather is 'firm' so I did not want to apply pressure to make the leather conform when stropping a razor, it does however work on a heavier blade eg a pen knife. The width is 1 1/2". The wet forming you describe looks like a good solution - I'll post how it goes.

On the positive side I now know how to post pictures!

Cheers!
 
1,5 "? It really shouldn't be cupping. I think it is dried out and possibly much too stiff leather to begin with. You could first try oiling it a little then rubbing it vigorously up and down along a smooth counter edge. You may have to do this anyway to soften it up after wet forming.

regards,
Torolf
 
Back
Top