Cow Gum For Marquetry

[Gill]

I've finally been able to get some time in the workshop (yippee - at last! ) and decided to try marquetry with a scroll saw. Previously when I've tried to cut marquetry with a scroll saw, I've met with utter disaster as the fine veneers splinter. Today, I enjoyed more success , although my work is definitely not elegant and there are some embarrassing errors.

The big problem I encountered was in stacking the veneers together. With simple patterns and thick veneers, they can be pinned together using veneer pins. However, for more intricate designs and thin veneers which require support, they need to be glued together with an adhesive which can be removed cleanly and easily after cutting. Today I used Copydex, which is fine up to a point but is rather expensive and doesn't last long. In the past, marquetarians used cow gum as an alternative.

Is cow gum still available or are there other substitutes?

Gill

 

[jasonB]

Cow gum has not been available for several years, nearest match is "Fixogum"

http://www.greatart.co.uk/MARABUFIXOGUM ... design.htm

Jason

 

[Gill]

Thanks, Jason. That sounds like the stuff I'm after .

Gill

 

[Tusses]

hot melt glue gun ? comes off when you warm it up again !

dont know if it stains tho , you'd have to try it on some scrap

 

[Gill]

I don't think hot glue would work quite as well as Copydex or Fixogum because it's rather stringy, sets solid very rapidly and would be more difficult to separate than either of the other two. Mind, if Copydex hadn't worked, hot glue would have been my next port of call, so it's definitely a good suggestion .

Those of you who know me will be aware that I first took up scrolling eighteen years ago as a means to mechanise marquetry. Until today, I've never had any success but...

It's a very small, basic motif which I found surprisingly difficult to cut accurately with the table angled at 25 degrees. So I need much more practice but I couldn't resist showing everyone a piece which, for all its simplicity and faults, means the world to me .

Gill

 

[Tusses]

well done !

 

[StevieB]

look very good to me Gill - especially if you have the table tilted! what thichness is the timber?

Steve.

 

[Gill]

Thanks .

Steve, I believe the veneers are 0.6mm thick, but I haven't actually measured them. They're just some off-cuts I had hanging around the workshop.

If I was working on a major project, I'd calculate the table angle precisely, but for this piece, I wasn't particularly concerned about getting the angle spot on - I'd have been happy enough just to have the veneers avoid splintering. I guessed that a table tilt of 25 degrees would be about right, and I was fortunate to judge it accurately enough.

Now, I bet someone will do the maths and tell me I should have set the table at a wildly different angle :lol: !

Gill

 

[NickWelford]

See

http://www.cowgum.co.uk/

However, there is an alternative

http://www.discountart.co.uk/Studio_Gum ... nAod2jvyWg


I well remember my father always had a tube of cow gum around - used it to mount photographs. Wonderful stuff.

 

[tnimble]

When using thin veneers with small sizes I stack the 2 or more veneers on top of ech other and hold them in place with some pieces of masking tape. When the veneers are larger glue them on some paper (hide glue) (the paper can also be your design). After sawing a piece fit it with veneer tape on the front side. When all pieces are done and glued on the backer matrial the veneer tape can be scraped off and ligtly sanded. For the table angle 7 degrees seems to do well.

 

[Anonymous]

To me, the most obvious way to cut thin veneers is surely to sandwich them between 2 pieces of thin MDF or ply. :wink:

I must admit though that I am not into marquetry so I'm sure someone who is will correct me if my idea isn't practical.

 

[jasonB]

The problem with putting them between two bits of board is that you can really only cut vertically. The reason the table is set to an angle is so that the top piece is larger than the piece below by the thickness of the blade kerf. That way when the two are put together there are no gaps.

Jason

 

[Gill]

Laura - your technique might be successful with simple shapes, but if you try it with shapes that are more convoluted you'll find that fine pieces will either break off during cutting or they will break when the masking tape is removed. I couldn't have used your technique with the dog motif because the protruderances between the ears and the head would have broken. I'm surprised you find you only need a table angle of 7 degrees; in the older days when veneers were thicker, the standard angle was 15 degrees(-ish). Nowadays veneers are even thinner which was why I opted for an even more acute angle.

Alan - as Jason says, that technique is okay so long as you are making vertical cuts. However, it will leave a gap between the pieces equal in width to the kerf of the blade. By cutting at an angle, the edges are chamfered and fit together snugly.

Nick - Thanks for the links . It's nice to have alternatives.

Gill

 

[tim]

Well done Gill

Here's a piece of marquetry to aspire to:

Done by a very talented pro friend of mine. My wife saw it and said - ooh, lets have one of those :roll:

Cheers

Tim

 

[tnimble]

Gill, the dog design is what I would consider a medium size marquitry piece. Low tack masking tape does not harm the small pieces it just about has enough stickness to hold the pieces while sawing. With the paper support glued on the back both the paper and the glue binds the wood fibers to prevent splintering and breacking.

Both the veneers and blades are thinner which allows the angle to be reduced. The more acute the ctting angle is in double bevel sawing the less smaller a piece can be. With 7 degrees the pieces can be very small and provides a near seamless joint.



That's a beautiful panel you show there tim.

 

[Gill]

That looks nice, Tim. Was it cut with a knife or a saw? When are you going to emulate it? Come on, it's not as difficult as it looks . There are some excellent marquetarians around and I particularly like the work of Bernard Rottenfus.

Christian - can we see some examples of your marquetry please? It sounds as if you're much more experienced at this game than me and I'm always willing to benefit from the experience of others.

Gill

 

[tnimble]

Unfortunately have not done some for while a while now and did not had a camera at that time. I'm about (or at least hope to have the time soon) to do a set of winding sticks with marquetry, ivory inlays and gilding ( :shock: yes I know)