Thread: gum in joinery

Hi Helga,

I use and sell salvaged Forest Redgum for bench tops in Brisbane in Slab form.As the material I sell is Air Dried (12-15% moisture content),I have had no problem with widths up to around 800mm.When I dress the Slabs ,generally from 50mm nominal to finish 40mm thick,anything over about 800mm can want to sometimes curl up on the corners as you are changing the surface tension and opening the face up to the air after dressing(especially in low moisture climate).The main issues are that as a specie it is suitable for bench tops but certain variables apply and issues to be considered if its not dry-eg cupping/shrinkage.I found Slab tops should be fixed shortly after dressing .Re your post you sound perhaps you may be laminating in width so may remain quite stable but not always as impressive as Slab full width face.

Regards,

Brodski

Thank you.Stunning photo, I have heard that for a kitchen bench it was compulsory to laminate it, but if it isn't necessary of course I would love to have a single piece to really let the piece of timber shine. So, if I want to do a bench that is 1570mm long and 620mm wide, is it possible to do it in a single piece only 25mm thick or is that physically impossible. When you say fix soon after dressing, do you mean in terms of days or weeks. Are you relying on the fixing o hold it staight. Do I ask stupid questions?

Originally Posted by helga

Thank you.Stunning photo, I have heard that for a kitchen bench it was compulsory to laminate it, but if it isn't necessary of course I would love to have a single piece to really let the piece of timber shine. So, if I want to do a bench that is 1570mm long and 620mm wide, is it possible to do it in a single piece only 25mm thick or is that physically impossible. When you say fix soon after dressing, do you mean in terms of days or weeks. Are you relying on the fixing o hold it staight. Do I ask stupid questions?

I am sure others will not agree with what I ahve to say her but her goes.
It the timber is dry Truely DRY when it is dressed and there are no inbuilt drying stresses released in the dressing process then it will stay flat unless the two sides of the timber absorb different ammounts of moisture or at different rates.
By way of example if you finish only one side of a riece of timber and humidity rises thenit will cup towards the finished side.
In answer to your question Lamination is nor required .

Ross

Originally Posted by helga

hi. I have had varying advice about using Eucalypts in joinery. Does anyone think it is possible to make a benchtop out of Forest Red Gum Eucalyptus tereticornis? What would be the maximum width and length of strips to avoid cupping?

I'm by no means an expert on timber......I can say that I have a workbench top thats made of recycled redgum,,,very old stuff that must have been very dry at glueup.....its about 2metres long, 2" thick and its width comprises of 3 planks edge glued together.....for a total width of (guessing) 600mm.....the edge gluing is just butted, ie, no dowels, no tongue and grove etc......yet it hasn't moved, no creeping of glue lines etc ...... and its a couple of years old now....

might help ???? goodluck

Thank you. Would finishing both sides of the slab or laminated bench reduce risk of movement or would that give the moisture nowhere to go? Am waiting to hear back from a local sawyer about availability of dry as Forest Redgum. If the quantity is not available down here, could I get the contact details of the slab salvager in Brisbane please.? Is it possible to have a slab 30mm thick?

Would finishing both sides of the slab or laminated bench reduce risk of movement or would that give the moisture nowhere to go?

Best to apply the same finish to both sides of the benchtop. You dont need to be as fussy about the finish underneath of course. If the top is varnished or similar and the underside is bare wood then the lower side will loose / absorb moisture much faster then the top. This change in moisture happens naturally as a seasonal thing, and if it's slow and even on both sides it wont have much effect. Just sometimes the mc may be 8%, a few months later it may be 10% ( depends on your climate). As you can imagine if you get a weeks wet weather and the slab ends up with one side at 10% and the top still at 8% under the varnish then the cupping will be noticable.
Applying the finish also slows down the transfer of moisture in and out of the wood, which is a good thing as well. You dont want the moisture to come and go, it's just you cant prevent it. Of course you need to mount the top so it can move slightly with seasonal variations.

I cant comment on the redgum as I've never used it, but I have done tops with 30mm solid Cypress that are stable. It's a very forgiving wood with regard to movement of course. Results will vary with other timbers,

Cheers

Ian

Hi Helga,
the reason I mention fix it shortly to base or carcass is that it is just a safety measure so it doesn't cup or moveif any major humidity variation between supplying and fixing ,not that in a 620 mm width you would have a problem,more so table top slabs.I can sell you a salvaged piece of Forest RedGum and organise it to be dressed and sanded on a Slabmaster machine that levels the Slab and can sand top face,usually 120 grit.Most of my Slabs are 50mm thick in the rough and usually for bench tops I dress to 35-40mm thick.You can contact me by email or P.M. for further details / pricing etc and whether you want to keep natural edge or cut square.I am in Rocklea on the Southside of Brisbane.
Email- [email protected] or Ph. 0409584707

Regards,

Brodski

very good Brodski! I have many duties to perform presently, eg lighting the fire, cooking up some bacon and some beans BUT I will contact you in the next few days about this slab. I am very interested, particularly as I imagine the salvaged wood is very dry???thanks, Helga

Do I ask stupid questions?

No such thing as a stupid question, its the stupid answers that you have to watch out for. (And I can provide plenty of those )
I think that you will find some really informed users on this forum (except for that Clinton user guy) - which makes it a great resource.
Have fun with your slab and post a pic when it is done.

Thanks Clinton

I think this forum is a bit addictive, I can't stop reading the archives!
helga

Brodski, that is a fantastic vanity setup.

It's so close to what I'd like to do for myself. Where did you find the beautiful basin? I've decided to not build my new vanity until I can get an interesting basin, something preferably not standard white from bunnies/mitre 10.

Thanks
RufflyRustic

Tim and Cameron at Lithgow Pottery make ceramic basins and also ceramic water coolers as well as many exciting sculptures and huge pots you could put a 7 yr old in. Sorry I don't have number on me. They're at western extremity of blue mountains.helga

Thanks Helga.

Does anyone else have any leads on interesting vanity basins?

thanks
RufflyRustic

This thread finally made me join. I built this bar a year ago with " western gympie red gum aged for 80 years" slabs. Ibought them rough sawn and went to town on them for a few hours with a belt sander. They were rough edgeed like in brodski's photo til i ripped the sides off (different strokes - different folks).
You can see the join on the top part of the bar(in photo) has been very stable. This join is dowled and glued and the slab varnished on top and underside.
The bigger bench join has moved slightly (photo looks worse than it is - extreme close up.) This part of the bench was hard to join due to the acute angle so i just glued and attempted to skew screw together, it is also screwd down to the studs holding the bench up. This part of the bench is only varnished on top. So i dont know if you can read into that re not sealing allround, but i personaly think it is just the size of the join.

Seeing as this thread is in the same vain. Does anyone have any experience of making kitchen rail and stile doors out of red gum, can you get plywood with a redgum veneer, also anyone have suggestions of suitable source for this purpose????? Yes my next project is the whole kitchen yippee:eek: