Working with hardwood (Greenheart & Purpleheart)

[Stu_UK]

Hello...

I'm hoping you guys can help me with a little project I've started working on to make a coffee table out of hardwood. The wood I've bought is Greenheart and Purpleheart. Both types came from a local wood recycling store. I've got 4 pieces of Purpleheart use to be used on the decking of Brighton pier; 3 pieces of Greenheart looks like a couple of off cuts.

The dimensions of the wood are...
PURPLEHEART
127x12x4.5 (X3)
100x12x4.5

GREENHEART
98x23x11.5
65x23x8 (X2)

The plan is to use the longest piece of Greenheart in the middle of the table top that is sandwiched either side by the Purpleheart. I think the contrasting colour will look pretty good. As the Greenheart is thicker than the Purpleheart I'll be joining the pieces of the Purpleheart together to make two lengths of it (dimensions 100x12x9). The two short pieces of Greenheart will be used as the legs with them running horizontally underneath the width of the table top. As the Greenheart will be thicker than the Purpleheart there will be a "channel" cut away in the legs that the Greenheart will fit into that will enable the Purpleheart to rest against the top of the legs. The dimensions of it once complete will be approx 98x67x32. I've knocked up a diagram of how I want it to look if anyone wants to see it.

The reason I'm asking you all for help is that I've heard that these types of wood can be difficult to work with due to their hardness. I'm going to need to cut most of the wood to size as well as sanding and joining together. My questions are:

1. I have access to a table saw but what blade should I use to cut such tough wood? I take it that it'll need to be a carbide blade. Any links to sites that sell them will be useful.

2. What should I use to sand the wood to take it down to clean wood? Should I plain it instead? I've got a sheet sander (which I guess won't to a whole lot against this wood) as well as a angle-grinder. The guy at the wood yard recommended using an angle grinder with a sanding head. Again, any links to sites that sell the type of thing I should go for would be good.

3. Is there any particular type of wood glue to use to join the Purpleheart together?

Also, if anyone has any tips or advice on how to do all of this it would be greatly appreciated. Let me know if I should look into buying any additional tools that would help with the job.

Thanks for your help,
Stuart

 

[jasonB]

Hi Stuart, welcome to the forum, good to see you found your way here. Most members are probably out in their workshops so you may have a few hours to wait for another reply.

Here is what I said to Stuart on another forum:

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You will need a table saw with a 300mm dia blade to give enough depth of cut to go through th egreenheart, Something like a 24 general purpose blade will do and as you say TCT, have a look at screwfix, wealden tools, axminster power tools.

Unless you want a very rustic looking table you will have to plane the surfaces particularly the ones that are to be glued so that you get a nice tight joint. Ideally an electric planer/thicknesser is what you need then the surface can be sanded before applying a finish.

Either a PU (polyurethane) glue or alphatic resin such as "Titebond" will do, the PU will help fill any gaps if you handplane the joints and don't get them perfect.

You may find it better asking on a woodworking forum such as this one

Jason

 

[woodbloke]

Welcome to the forum - take care with greenheart as the splinters are toxic - Rob

 

[Waka]

Stuart

Welcome to the forum.

Mahking51 has a lot of experience with greenheart, he made his bench from it, I'm sure he'll be along shortly to offer advice.

 

[mr]

Ive just used some purple heart for a small project and found it to be truly horrible to work with. It seemed to be very "brittle" lots of tear out and the best way of planing it I found was accross the grain with the splane set for a very fine shaving. As for sanding it I found every grade of sandpaper up to 400 left scratches that I couldnt get out. The solution was card scrapers which left an ok surface but not brilliant. Others here have said that powered sanding worked for them but I didnt have any luck with that, hand sanding was better but still the scratches.
Mike

 

[Newbie_Neil]

Hi Stuart

Welcome to the forum.

Cheers
Neil

 

[Stu_UK]

Thanks for all of your replies guys.

How should I go about cutting the Greenheart & Purpleheart? TBH I'm quite a newbie when it comes to furniture making! JasonB mentioned a carbide tipped 24 general purpose blade. Will I need a couple of these as I need to make at least 4 cuts of the PH and 3 of the GH? How quickly will the blade dull?

Both the PH & GH will need to be sanded or planed down about 1mm to get rid of the surface. Would an angle grinder fitted with a sanding flap disc be okay (e.g. http://www.tooled-up.com/Product.as...p-Disc-diam-180-mm---60-Grit---Blue-metal-Top)?

Thanks

 

[paulm]

A lot depends on what kind of finished effect/style you are after Stu ?

Angle grinder and flapwheel or similar may be okay if you are after a rough and ready chunky rustic look, different matter if you want a finely finished fine piece of furniture.......


Sorry to be a bit vague, can you tell us a bit more about how you want the style/look to turn out ?

Cheers, Paul.

 

[PowerTool]

I've used purpleheart for turning a couple of times - it seems to just come off in small flakes/chips rather than shavings.
Power sanding works on it,but it seems to suffer from heat checks so gently does it.

Andrew

 

[Stu_UK]

I'd like the piece to look chunky and modern so it doesn't have to be too finely finished. As long as there's no sharp bits on it, it'll be okay...I don't want any guests to end up with poisoning from the GH just because they touched the table.

 

[mahking51]

Hi Stu-UK,
As Waka says I have a vast amount of greenheart and made my bench from it, laminated in 2" wide x 4" thicks strips. Very hard on the planer and thicknesser blades and hand planes are back to honing evry few minutes else they just skate over it. I had to pay the sawmill extra for sharpening when milling the raw 14" x 14" stock. Splinters and dust are nasty so wear masks and take care.
If you wantto see the bench try a search on greenheart and/or bench.
Its a bit bland sometimes but a nice piece gives a lovely glow when oiled but not a lot of figure.
Have fun and good luck.
Martin