Thread: Jarrah Slabs in need of flattening

Originally Posted by cfrancisl

Hi guys,
I have been playing with the idea of setting up a homemade jig with my old makita router and sliding it back and forth to level the slabs. Does anyone have experience with this?

Cheers,
Chris

This months Australian Woodsmith magazine has an article on doing just that along with the sized plans for making the jig. Issue 84.

Originally Posted by Talorien

This months Australian Woodsmith magazine has an article on doing just that along with the sized plans for making the jig. Issue 84.

Thanks Talorien,

Checked out the Australian Woodsmith and seemed I needed to subscribe for 6months/12 months. I have an idea of what I want to build but thought I would run it past the forum.

What do you think? All sliding surfaces will have some kind of laminate and it will all be made from mdf. The width of the sliding part the crosses between the rails depends on the router I will use (have a couple of makitas which will do it). Its made big enough to flatten the largest slab I have.

Cheers,

Chris

I recently used a jig roughly based on the one previously described from Aust Woodsmith. I dont have a jointer and needed some timber flattened on one side before sending them through the thicknesser.

I was only flattening small pieces (up to approx 250mm wide, 1000mm long and about 50mm thick) so screwed the side rails of the jig to an MDF base. It worked pretty well.

I used a Carbi-tool planer bit (TSS 13 1/2), it was great for the job but a bit expensive, and although it was pushing my Makita router (being a rather large bit (50mm wide) and with no variable speed to slow the router down) they came out nice and flat.

The only down side is trying to keep the timber from moving about whilst planing and the fact that it is a bit time consuming (and quite dusty if you dont have a router that takes a vac). It may take you quite a while to do your 10 slabs.

Let us know how you get on.

Steven.

Check the timber and milling forums, there may be someone with a Slabmaster or similar machine who can do it for you.

Hi Cfrancise,

I've flattened a fair few slabs over the years using the router with a longitudinal and cross slide template technique.I haven't tried Jarrah or anything near as hard and dusty.

It's essential that the timber is rigidly attached to the bench or you will be chasing your tail and getting nowhere. It's a good idea to remove a high proportion of the waste first up using a hand held electric planer and checking frequently with a pair of good winding sticks before starting the routing process.

When I had to use this process I used to plane a track cross grain at either end of the slab and work on these with plane and winding sticks until I had a pair of fairly true reference levels to work to when removing most of the waste with the hand electric plane. Whatever way you go it is absolutely painful in terms of time, noise,dust and cost of sharpening cutters.

Be sure to use the true reference of the top face when prepared to then true up the bottom side.

I now have fee paying access to getting jobs done on a Slabmaster which is an infinitely superior way to go. Quite easy to true up a 2.4m x 1.2m slab both sides in about 1 1/2 hours and much less if you go the route I have suggested above for the router method.

If you can get access to this technology I suggest you don't bother with the Slabmaster sanding function. Just do the flattening on the Slabmaster and then take the accurately flattened and thicknessed slab to a joinery works with a wide belt sander. Just a few passes at 100g will give you a top surface ready for fine finishing at home.

Good luck; I have to lie down for a bit now thinking of working through 10 Jarrah slabs. I'd have to be getting the neighbours in pretty frequently to move that lot around the workshop through the stages.

Old Pete

Good Luck

I've done a few slabs with that method and its pretty straight forward. I suggest you start with the slab that will need the least amount of work as you'll pick up a few things with experience. The main thing is setting the stab and depth of cut up right then making sure it doesn't move as Old Pete mentioned.

Hi Chris
I have home made jigs you can copy made with MDF, one is for small burls (Pic 1 jarrah burl ) and other has metal rails with MDF Carriage is for bigger slabs (Pic 2 mari slab 2300 x 700)
Currently in process of making a larger one

Dazza

Yes, I've also done this, and as others have pointed out, it's important to keep the material fixed in place (I screw it to the bench). The drawing you posted looks okay, but I would add rails at the ends of the top piece to prevent it from twisting in a horizontal plane. You might also consider a metal cross brace to stop it sagging in the middle. It is time consuming and generates a lot of dust/chips, but it is possible.

Hi Chris
I have a wood wizz arriving in 5 weeks if this helps
Dazza

Hi guys,

Not a lot has been happening with the slabs lately, Just cut the worst one up for firewood..

Thanks for advice about fixing it to bench and creating sturdy frame for router to slide up and down on... The one you posted looks good Dazza. I think I will try and make a larger version of that.

I will be doing various smaller pieces of burl first to test it though.. will post pics in coming weeks.

Chris

Hey chris
you can have my set up, i ordered a wood wizz.
Shame to hear about the firewood
if you want to save a lot of time and dust, you can bring a slab or two over when wood wizz arrives
Dazza

Dunno how I missed the start of this thread.

I've been in the same situation a few times and have settled on what I think is a good solution.

For the side rails I've managed to score a couple of nice, long - and straight - galv. C-sections that were used for the sub-frames on 1-tonner trays. My ply cross-member slides along these very nicely and as a bonus they double as straight edges for brick- and slab-work.

My first attempt was much along the lines of your diagram, Chris, with the router sliding along a slot in the cross-member... In practice this turned out to be a headache to use. Constantly making sure the router was sitting flat while sliding it and making sure the cross-member didn't slide off one of the rails at the same time was a PITA. A sure fire way to put some nasty gouges in your work. DAMHIKT.

To prevent the cross-member sliding off, on my Mk 2 version I added stops... but then it became a headache when moving the cross-member along the rails. If I didn't slide it squarely, it'd bind. Not a real problem, but it did make a long tedious job even more tedious.

My solution for Mk 3? I've made a very long cross-member, over twice the width of the widest slab I expect to ever handle, to which the router is bolted securely in the middle. To ensure the router bit never says hello to Mr. C-channel I screw a stop on the underside of both ends to suit each individual slab.


In use it take a bit more effort to throw around, of course. But as it means I can keep my eye on the router bit rather than trying to watch three or four different things at once, I am content.

Originally Posted by cfrancisl

Not a lot has been happening with the slabs lately, Just cut the worst one up for firewood..

You're kidding right? Even if you can't use them as a table top, they would be incredible valuable to turners as platters, bowls etc.

Originally Posted by sjm

You're kidding right? Even if you can't use them as a table top, they would be incredible valuable to turners as platters, bowls etc.

sjm, he's from Perth, WA. They used Jarrah for railway sleepers over there!!
I don't think he's kidding about the firewood.

Tom