Thread: How would you do this

Two suggestions:

Removing glue - get a set of cabinet scrapers and learn to sharpen them. They should be much less aggressive than sand paper, so there may be less tendency to wear through the dyed layer.

Dyeing: Make a vacuum chamber. They are not too difficult to make, and if you feel you lack the necessary skills you could enquire on one of the metalwork sub-boards for someone to weld up the box. Your main difficulty would be sourcing a satisfactory vacuum pump if you find you need a 'high' vacuum, otherwise an old vacuum cleaner can draw a modest vacuum. Then you just put some veneer pieces in a container of dye (say, an old take away container) in the chamber, put the lid on and suck away. When the veneer stops fizzing, release the pressure which will force the dye into the veneer. Allow it to air dry, possibly in a press with absorbent sheets. If you want it super dry, return it to the vacuum chamber when it feels dry and vacuum dry it by again exposing it to low pressure, this time for several hours. Also when planning a vacuum chamber, plan to make it juuuuust big enough to hold your project - this will reduce the time it takes to drop the internal pressure and make the chamber stronger/allow you to use thinner material for the chamber.

Originally Posted by bsrlee

Dyeing: Make a vacuum chamber. They are not too difficult to make, and if you feel you lack the necessary skills you could enquire on one of the metalwork sub-boards for someone to weld up the box. Your main difficulty would be sourcing a satisfactory vacuum pump if you find you need a 'high' vacuum, otherwise an old vacuum cleaner can draw a modest vacuum. Then you just put some veneer pieces in a container of dye (say, an old take away container) in the chamber, put the lid on and suck away. When the veneer stops fizzing, release the pressure which will force the dye into the veneer. Allow it to air dry, possibly in a press with absorbent sheets. If you want it super dry, return it to the vacuum chamber when it feels dry and vacuum dry it by again exposing it to low pressure, this time for several hours. Also when planning a vacuum chamber, plan to make it juuuuust big enough to hold your project - this will reduce the time it takes to drop the internal pressure and make the chamber stronger/allow you to use thinner material for the chamber.

Very interesting. I have never heard of using vacuum for dying - most people concentrate on using high pressure. Have you done this and what measure of penetration did you get ?

cheers
Arron

Arron, I would give one of these a go for removing glue squeeze out.

Nice work Arron - almost Japanese in its feel. I do not do marquetry so cannot offer direct advice, but it seems to be the sort of problem that others must have faced, and solved. Hopefully someone will post.

If you try bsrlee's pressure chamber technique, then an old pressure cooker may provide a ready made chamber - they only cost $10 or so from any op shop or tip shop. You might have to replace the rubber seal but they are readily available.





Fair Winds

Graeme

Originally Posted by Arron

Very interesting. I have never heard of using vacuum for dying - most people concentrate on using high pressure. Have you done this and what measure of penetration did you get ?

I can't speak for how it affects dyes, but I use a vacuum chamber when stabilising small, punky pieces of wood.

It's not as efficient as high-pressure; a vac. will only pull down to a maximum of 1 atmosphere differential, while high-pressure can be multiple atmospheres. Consequently, using a vacuum makes it a slower process, that typically gives less penetration. (ie. days rather than hours)

Given that:

1. A vacuum rig is much cheaper to set up initially as it can be constructed from second-hand "household" products & appliances.
2. Due to the lower pressures, a vacuum rig is much safer to operate, especially if you don't really know what you're doing and don't have a convenient mentor standing by.

If you're giving thought to trying this path, then I would suggest that you set up a vacuum chamber first and give it a test run or three on small pieces of scrap.

If it gives you sufficient dye penetration then you now have a new tool at a fraction of the cost of a true pressure vessel. If not, well...

(When all is said and done, I want a good pressure chamber... in the same way I "want" to replace all my tools with high-end counterparts. But until I win Tatts, a vac chamber will have to do. )

Not as good as a vacuum chamber, Arron, but you'll get deeper dye penetration by heating the dye, then dropping the pieces to be dyed in and waiting for the lot to cool. Hold the pieces under, initially, then let them float.
The timber heats, forcing some air out, then when it cools it sucks the dye in. You still won't get full penetration, but better than when done cold. I use water-based (UBeaut) dyes, but it should also work with spirit-based. Just sit the container in a pot of hot water to heat it, double-boiler style.

Around glue-ups, I often use paste wax on surfaces I don't want glue to stick to, then wash it off afterwards with white spirits. A toothbrush can help with that. Might be tricky on small pieces of veneer, though, to wax the top without getting wax on the underside.

Nice work, by the way.

Hi Arron

I know very little about marquetry, but ...

can you dye the "special" pieces,
assemble the pattern right side up on a transfer sheet *
coat the pattern with wax,
cover with contact paper,
transfer to the glued substrate

once the glue is dry, squeeze out should easily clean up off the wax


* the transfer transfer sheet I've seen used is a clear contact with a low tack glue -- a bit like the glue used for Post-it notes

Thanks guys, some good suggestions there to think about.

Just responding to a couple of them. About the dyeing, the method using heat and cooling (as Steve suggests) is how I do do it. Usually heating at near-boiling for one hour, then cooling and drying off. I might try the pressure cooker thing, but thinking about it, maybe I should just bite the bullet and buy from overseas. Like here -> Dyed Veneers . The veneer is actually really cheap, and lots of colours. I've just paid $130 postage to import a quantity of burl veneer about the size of a telephone book so I guess I'll do it again. Anyone want to go in on a group purchase ???

The wax thing might be worth a try as well. I've been put off trying this because of concern that getting a bit of wax somehow on the underside of the veneer will prevent the glue bonding. When gluing up and putting in a press it gets a bit messy with the veneer curling and sliding around so you tend to have hands all over the place, and it would be easy to transfer a fingerprint of wax from top to bottom. You can use contact paper to cover the surface (as I do) though it has negatives as well, such as the inability to manipulate a wayward piece which has come loose at the last moment. It might be time to give wax a go though. One option might be to put wax just around the particularly gappy bits of marquetry and then cover it over with veneer tape so that you can touch any bit you need to with impunity.

I've also just read about people putting absorbent paper between the veneer and the press caul, so that the paper wicks any squeezeout away from the surface. Not sure how this works but could be worth some experimentation.

cheers
Arron

you could try TopVeneer - Quality Timber Veneer. Jarrah figured and Natural Timber Veneers - Products - Finewood Ventech as they might have what yuo are looking for as the top veneer har figured jarrah. I recentely cleaned up a compass star with a cabinet scraper and it worked well but for some finer parts i used the blades from a Retractable Safety Scraper and it worked quite nicely.