Thread: Gluing ironbark

Firstly welcome to the forum.

You have asked quite a few questions I am not going to be able to give you worldly experience answers as I have not worked with Ironbark. As you would be gluing long grain with long grain you will end up with a very strong joint I think the main reason to biscuit would be for alignment.

To fill holes I have used epoxy tinted with a black dye, the final decision is really up to you as to what looks good. You might want to test on some off cuts and apply a finish to see what it looks like gloss or matte. If you do go epoxy path, I have done in a couple of mixes so that I can build up a little at a time.

Sounds like a quite insane commission considering you will have a table upwards of 200 kg like a massive workshop table. Anyway you are gluing so much area white glue (pva) will do it easily. A biscuit each end for alignment as Christos said. Fill the holes with black tinted epoxy (plug under first to stop running through). Sand with belt sander from 80 up to 240 or 300 grit then random orbital sand and finish with two coats of flat varnish, sanding with the ros between coats. Don't use stain or you will just ruin the colour. If you want it to feel nice rub the whole thing over with traditional wax (Ubeaut) on fine steel wool and buff it off with a cloth.
For the bench tops you really should have the 90x90 ripped into 3 90x25s or 27s and thicknessed down a few mm then assemble the bench tops out of that. Same as above, white glue and a few biscuits. 25mm is easily thick enough for bench tops and tables too for that matter. Most tables achieve a thick look by having an additional piece that runs around the edge.

I've never used ironbark, but based on experience with other eucalypts, these are the things to watch out for.
Will the glue stick to the wood? With some eucs, you need to clean the surfaces with acetone before gluing. If you do this, the glue will probably be stronger than the wood .
The wood may move. Some eucs will continue to move forever, some are extremely stable. I don't know about ironbark, but if it does want to move, it will do so, splitting the wood if necessary.
Filling can be done with either casting resin or epoxy. As Len says, tinted black would probably look best. Also, finish as Len suggests.

Personally, I'd rip it down thinner as suggested.

As above, but I wouldnt be trying to glue up all the pieces at once. Would be a lot easier to align if say three pieces were glued together at a time and when dry, the groups of three then glued together.

Re: filling the bolt holes. I would cut oversize, tapered pegs in a softer timber and bung them in till they went round or the hole deformed. They will look better than plastic everywhere.

Originally Posted by Bennetto

Hi all, pardon the new thread with my first ever post, but I couldn't find any threads with a substantial answer. I am doing a Cafe fit out in central Melbourne and the client has purchased a tonne of recycled ironbark for me to build all of the bench tops with

The lengths are 2.5m long x 90 x 90 and as you can imagine extremely heavy, the main table is to be 2500mm x 1200 meaning I will have to panel at least 15 lengths together.

First question, after I machine the edges is there a glue strong enough that I can use without buiscuting? I've heard a German glue named kleiber is really good... Or bond rite 3??? But with my lack of experience with iron bark I'd just be guessing.

Also they are full of old bolt holes, which the client loves, (rustic look) what is the best thing to fill these with, they range from10mm in diameter to 25mm.

Lastly the client wishes to have a matte finish, am I able to just sand a glossy epoxy? With some brown oxide in it?? Any suggestions for these problems are more than welcome, as I feel a tad lost.

Much appreciated

G'day Bennetto,

Do not use epoxy as a finish coat if it is going anywhere near direct sunlight. Epoxy has very poor U.V resistance (may only last weeks, yes weeks, in the sun). Much better to use urethanes or oils and de-glossing additives are available for urethanes.

Regards, Timboz

I used Titebond III on my reclaimed ironbark bench build. So far it seems to be doing the job and an earlier project made from brushbox hasn't had any delamination issues either. I'll second the concern about weight. My workbench at about half the size of your table, weighs in at over 100kg and just handling the individual lengths through planer and thicknesser was challenging, I got very practised at splinter removal.

I would think about doing some testing on a few glue types to see what holds best especially if you are relying solely on the glue to hold the joint together (without mechanical fastening) make up some dummy joints from scrap pieces then try to break the joint, I have had success and failure with the Ironbark I have glued, being a dense timber and not easy to prepare an edge ready for gluing (using handtools) (which should be done after machining) also adds to the difficulty.

Here's a few repairs of faults and bolt holes in some brushbox using timber plugs, in the last pic you can see a couple of the bolt hole repairs
bolt hole.jpgplugged.jpgcut off plug.jpgsanded off flush.jpgtop prefinish showing repaired bolt holes.jpg

Some natural faults
fault.jpgplugged fault.jpgsanded flush fault.jpgfault 2.jpgsanded flush fault2.jpgfault 3.jpgrepaired fault 3.jpg

Fault 2 above is plugged using a long grain plug, all others are end grain which means they will stand out a little more against the long grain and maybe be a bit "rustic" as your client likes,,,, all the natural faults were cleaned up using the router either in a straight line or circular fashion like the last one, I just drilled down into the bolt hole to clean it out.

For a flat finish y not just go for an oil.


Pete

Thank you so very much for all the handy hints, they have all been used to some degree. I went with a German glue called kleiberit, glued a few test pieces together.... A sledge hammer had no effect on the bond, amazing glue. Thanks again

What type of glue is it, Bennetto, & where did you get it?

Originally Posted by AlexS

What type of glue is it, Bennetto, & where did you get it?

Hi mate, so it's called kleiberit 501.0 and it's a polyurethane glues that kind of expands when drying. A place in bayswater Vic, called tekform deliver it for about $150 for a box of 12 tubes. Cheers alex

Thanks Bennetto.