The Purpose of Slabs

[Gosut]

I know this is a stupid question, but what is the purpose of a stone slab? For tooling, I can see the advantage of having a hard, smooth, surface. Other than that, is it to provide a rigid mass so that the work surface doesn't deform, allowing more of the energy from the mallet or maul to be applied to the piece? 

[GrampaJoel]

Tooling probably is what they are mostly used for.

I use  mine for tooling,

setting rivets,

punching stitching holes. With think leather between of course.

crushing ice… 

you name it they come in handy.

 

[Mablung]

It’s also good for skiving. Gives a very hard, smooth surface for the leather to sit on and a knife to glide over (especially with a head or round knife: the point can glide along the slab). 

[PeterinID]

In addition to the transfer of energy while tooling a big reason that stone is preferred is due to the fact that iron staining can occur if you use a ferrous surface (it can also occur if you have iron dust on your hands frome sharpening knives). A stone surface eliminates this - unless it is iron containing stone. Granite is most common

[SUP]

Essentially, it is to provide a firm surface to work on. All the things we do in leatherwork - from cutting heavy leathers to punching to skiving and so on, most work best with a hard surface. Granite gives the best all round function Wood would work for some but not others, same with metal. A single granite slab and one does not need to worry about whether the surface is appropriate for the current function.

At least, that is what I believe.

[tsunkasapa]

Tooling on a slab also drastically reduces the noise from banging on tools as opposed to doing it on a table or workbench  surface.

 

[Gosut]

Thanks all. What I was considering was that if it's the mass that helps, then I could use any similar rigid mass for punching, snaps, and rivets as long as I cover the surface. In particular is a cheap patio stone, which are made of concrete. Note that the leather wouldn't go directly onto the concrete, but on an old magazine, which I'm already placing under it. Possible drawbacks are the potential of a concrete "stone" breaking and would have to put something under it to prevent marring the work surface as well as on top of it.

Before anyone points it out, this is one of those ideas that could easily turn into spending ten dollars to save one, all for a work surface that's not fit to tool on.

 

[fredk]

I used to use a piece of concrete paving slab but I changed to a piece of marble I found because I found a skiver just glides along the polished surface of the marble. When I use a skiver to do an edge at an angle part of the skiver is on the marble and it just glides over it 

[SUP]

@fredk, How thick is the marble? Do you use it for punching too? I had one but it cracked ad a piece broke off. So I got a granite one. 

[Northmount]

13 minutes ago, SUP said:

@fredk, How thick is the marble? Do you use it for punching too? I had one but it cracked ad a piece broke off. So I got a granite one. 

The back surface of marble or granite needs to be flat.  And the surface you have it on needs to be flat as well.  A slab placed on a concave surface will crack and break when you pound on the middle of the slab.  It may take a few hits, or a few hundred hits, but it will eventually break, especially the harder you pound it.  Any little flaws in the material will result in breaking sooner than a slab with no internal flaws.

The thicker the slab, the longer it will last.  If you do any brick or stone work, you will learn the techniques for marking and breaking the material.

Some people place the slab on a bed of sand build into their bench.  Others on top of a towel, or rubber pad.  I have a very flat work table and bench.  I put a towel under the slab so it is easier to move, and so it doesn't scratch up the table or bench surface.  I have one small piece that is 8"x13" quartz (engineered stone) that was a sample for a counter top.  This small size is handy for portable use. I pasted a piece of felt to the back.  Should do the same to my 12"x24" slabs, or maybe even use a piece of leather since I have lots available.

 

 

[SUP]

Thank you @Northmount. I should do that - attach some felt to the underside of the slab I use, although right now it is placed on a silicone mat.  My marble slab was completely flat and used on a completely flat surface. Maybe it already had some flaws that I couldn't see.  I have no idea what to check for when buying such slabs.

[tsunkasapa]

5 hours ago, Gosut said:

Before anyone points it out, this is one of those ideas that could easily turn into spending ten dollars to save one, all for a work surface that's not fit to tool on

Go to a company that installs marble/granite counter tops. Most of them will let you pick through the 'bone pile'. My son got me a 24"x32" bench slab and a 12"x12" portable one for free.

Edited February 16 by tsunkasapa
typo

[fredk]

@SUP I only use my marble block for skiving on

I found this piece in a builder's waste pile* ; it is 18cm long to the broken edge, 10cm wide and 3cm thick

One thing I like about it, it has this bevel on one edge.  Thats come in useful  

I also have this re-constituted granite slab. Approx 17.5cm square by 2cm thick. It was a kitchen work top thingy which I repurposed several years ago

I've tried to get some thick marble or granite for a new bigger block but despite this country being being one of the largest exporters of granite I cannot get a piece. Local places (kitchen fitters, grave marker makers, et cetra) which use marble and granite use a thin veneer over concrete

As I don't, or very rarely, do tooling on them I don't bed them down on anything

* this piece started out much bigger. It was about 30 x 40 cm. I asked one of my son's mechanics to cut off 10cm. Being a furiner (Latvian) he did just that, but he didn't keep both pieces as I'd asked. He disposed of the 30cm square. Not just disposed of it, but took a hammer to it and broke it up into gravel sized bits! Then he handed me this 10cm piece, 'there you are, why you not want the big piece?'

 

 

[purplefox66]

Go to a Head Stone maker and ask for a waste piece. The one I have is 5 inches thick and it is the best for setting stamping or skiving. You can also go to a counter top place and get scrap I have gotten both for free.

[SUP]

@fredk, so that's over an inch thick. I should get a slab which is at least that thick - then I don't have to worry about it cracking as I work.

@purplefox66 I have not seen any headstone makers here but I see granite countertop makers everywhere. there are several near the Tandy store here. Not yet had the courage to walk in and ask. I should really do that, since the granite slab I use is rather large and very heavy to pick up and keep away each time.  A smaller one works so much better, so I still use the broken marble or work on the floor.

Edited February 16 by SUP

[Northmount]

@SUP  SURFACE PLATE 12IN. X 18IN. X 3IN. About 77 lbs.  Flat to within 1 ten thousandths of an inch.  $40 to $70 approximately and even higher.

These are available at places that sell machining tools and equipment and amazon.com

 

[SUP]

@Northmount sounds good and would be great to work on. Thank you. I just checked on Amazon. I will check nearby stores as well.

[Gosut]

23 hours ago, tsunkasapa said:

Go to a company that installs marble/granite counter tops. Most of them will let you pick through the 'bone pile'. My son got me a 24"x32" bench slab and a 12"x12" portable one for free.

Nearest one is a good distance away, though I drive past for a doctor's appointment (typical old age stuff, nothing serious).

Monument companies are easier, with two fairly close. Have been thinking about talking to them.

[Gosut]

21 hours ago, SUP said:

I have not seen any headstone makers here but I see granite countertop makers everywhere. there are several near the Tandy store here. Not yet had the courage to walk in and ask. I should really do that, since the granite slab I use is rather large and very heavy to pick up and keep away each time.  A smaller one works so much better, so I still use the broken marble or work on the floor.

Around here they go by the name monument companies. Usually it's grave slabs and tombstones, but they also do all sort of monuments.