laser-engraver Sanding NON-flesh/smooth side of leather.

[ivanlc]

Hi. I'm new to leatherworking, coming from the direction of woodworking.

I use a laser-engraver with wood, and am now doing the same with leather.

(I know it's usual to emboss leather, but I've no embossing equipment and couldn't make my custom designs with it anyway.)

Thing is, it's often the case that the laser-engraved work needs redoing for various reasons. With wood, this just means sanding or putting through a thickness planer. No problems. 

With leather however, this means sanding the smooth/NON-flesh side. Problems.

Have found posts regarding smoothing the flesh side, but not about re-smoothing the *outer/non-flesh* side to correct mistakes, hence why I'm posting this. 

I can't believe people make a mistake on the outer/non-flesh side and simply discard the leather altogether!

Have made up some of Dwight's beeswax & neatsfoot oil compound which he says he uses to smooth the flesh side, but I don't know if this will seal the leather and prevent dyeing if I use it on the outer/non-flesh side. (Also not sure how many layers of the compound to use and how long to wait between applying layers.)

Any suggestions/help/advice would be very, very welcome...(!)

[fredk]

Unlike wood, once you break through that tight grain of the hair side of leather its impossible to get it smooth and like its surrounds again. It will always stand out and be noticeable. It won't take dye and finishers like the rest of the surface

Basically; yes, if a mistake is bad enough the piece is scrap - a reminder to take more care. When carving leather we take extra care, extra time. A small mistake can be ignored, [eg; a line not straight, a letter not equal to the others, ] a bit bigger it can become part of the work, or a feature in its own right. Small mistakes are a feature of OOAK works. Some buyers look for the imperfections which says; this is hand made

[ivanlc]

Thanks for the reply fredk.

Given what you've said about taking greater care, since leather errors can't be rectified in the same way as with wood (which observation has also shown me), I will certainly take FAR greater care - and also make far more use of scrap pieces to experiment on...!!

But I have 3 workpieces with the hair side experimentally dyed/sanded that I don't want to waste, hence my original post about how best to proceed.

It's not a problem for me if the smoothness of the hair side is broken through on the above pieces, as I'd sand the entire surface anyway, so it'd all look the same, meaing (in theory, anyway!) the whole surface should be equally reactive (or not!) to whatever finishing method I use.

They are not display pieces and will be subject to much wear & tear, so optimal standards of presentation are less important than being able to personalise them.

So given the above, what would be the best way of treating/sealing sanded hair side leather with these pieces and if I ever have to do so in future?

Can I assume it would be like dealing with suede or nubuck?

NB: what does OOAK mean?

[fredk]

Leather has a grain, it has fibres. The fibres run everywhich way. At the hair side they are compacted together and get looser as you get into the flesh side. The strength of the leather relies on that tight fibre network. If you sand away the hair side, the grain side, you start to remove that strength; thats why when we need to reduce the leather thickness we skive off from the flesh side. A little bit of sanding might not show any reduction in the strength, but sand as much a 0.5mm and you weaken the integrity. The inner loose fibres no longer have the tighter packed fibres protecting and re-enforcing them. It may not show for months but it will eventually.

If you sand away too much of the top grain you are making suede. Ask a saddler if he/she would make a stirrup strap from suede or top grain leather

You have bees'wax and neetsfoot oil mix; thats fine for feeding the leather and smoothing the flesh side. To smooth the front grain side after sanding use plenty of bees' wax* on its own. Heat the wax, heat the leather, rub the soft wax into the leather, rub it well in and burnish up with a piece of denim or linen one the wax has cooled  >>* not with NFO as you don't want too much in the leather

 

OOAK = One Of A Kind = any hand made article

[ivanlc]

Wow Fred. Many thanks for your reply. This is the kind of stuff I'm after knowing...!

... Learned more from what you said than I have browsing the web, reading various articles/posts, AND from studying a leatherworking book I bought...(!)  

So the pieces whose hair/top-grain side I've sanded I'll keep for experimentation/my own use, rather than giving them away, as I'd originally intended to do.

Will give the beeswax approach to smoothing the sanded hair sides a try. 
(Btw, it's incredibly useful to know that NFO isn't good to include in a hair-side smoothing compound, which I'd not realised.)

I've made a burnisher following directions from the handbook I have (the burnishing edge is now smoother than anything I think I've ever sanded before...).

... But is it better to use a piece of denim/linen - as you suggest - instead of a burnisher with the beeswax to burnish/bring a shine the hair side...?

i.

[fredk]

With a piece of denim or linen  in your fingers you can rub the wax right into the leather, into any pattern you have engraved. Heat from the friction on the cloth and from your fingers will keep that wax soft and help to get it right into the depths of the leather.  Afair bees' wax melts at about 65 degrees C, so friction heat melts it well. Using wax cold, with a cold burnisher the wax will just stay on the surface and be reduced to very little first time its buffed up. 

I use bees'wax & neetsfoot oil mix on the flesh side, rubbing it in with a bit of linen cloth, then its bees' wax on its own on the grain side. Heating it with a hairdryer if necessary. After a day or so I buff up both sides using a soft cloth and a soft shoe polish brush

Its not so much that wax/nfo on the front/grain side is bad, if you use it on the flesh side you'll not need it on the front, without the nfo you can use much more wax without fear of using too much nfo. Too much nfo is not nice in a project, it leaches out onto everything it touches.

If your pieces were for display or modest use; eg outside part of a handbag or a briefcase, then sanding and waxing the surface would not be much of a problem but you said

Quote

...will be subject to much wear & tear. ..

so extra needs to be taken to make sure your piece is fit for purpose

Edited November 29, 2017 by fredk

[ivanlc]

Hi Fred.

I followed your advice re:: the beeswax & burnishing w/ a piece of cloth, etc; was preeeeetty damn happy w/ the results.

Only thing was, it's not easy to keep heat applied to the leather/beeswax to keep it liquid whist trying to burnish at the same time!

I came across a post on here that said you could mix the beeswax w/ turpentine/white spirit to keep the beeswax mixture from hardening whilst you burnish.

Is this true, d'you know...?

Edited December 6, 2017 by ivanlc

[fredk]

Sorry; I may have mis-led - heat just to get the wax into the surface, burnish when its hard, the heat generated by burnishing will be enough to work any wax on the surface into the leather and to even it out

[ivanlc]

Yes, I did this, but the wax hardens immediately upon removal of heat, plus keeping the leather itself warm isn't easy.

I even tried heating wax on my cooker at a low heat to keep the wax pliable (and heating the leather w/ a hair dryer simultaneously), but both kept hardening/cooling before I could apply the wax. 

This is why I wondered if mixing the wax with the white spirit (turps), as I'd seen in another thread on here, would keep the wax liquid so it could be used for the burnishing process - without damaging the leather.