Cumaru

Jeff · 06-11-2008, 09:59 AM

I'm thinking about building an outdoor table out of cumaru wood similar to those offered by Hatteras Hammocks. Probably gonna be about 30" tall with a 4 sf top. I can get a 10 bf pack of 13/16" surfaced S2S1E for about $110.

I've read that this wood does not glue well, but takes screws (pre-drilled) well. I'd like to laminate a few of these 13/16" strips to size up the legs to about 1" thickness. Any experience out there with gluing cumaru? Pre-wipe with acetone and what type of glue? Gorilla? Epoxy?

Cumaru is also reported to be real hard to mill. Carbide tipped saw blades and drill bits are recommended. How do you cut a good mortise & tenon joint in this stuff? It seems that it will just eat up a good sharp chisel or router bit.

Any other tips and advice on joinery techniques for this type of wood is welcome. Thanks in advance.

charlie s · 06-11-2008, 12:36 PM

Jeff:

I have one experience with cumaru and it wasn't a pleasant one: a trip to the emergency room. I'll confess to not following correct safety procedures but what happened was when I was routing the edge of a glue up, the wood shattered, grabbed the router bit and jerked it into my hand that was holding the piece. Yes, I should have clamped the piece down and used both hands but I've never seen wood shatter like that. This wood has a tendency to splinter similar to hickory so be very careful when using a router on it. As far as glue goes, I'd look into using plastic resin glue, although I didn't and haven't heard of any issues with the piece I glued up.

Charlie

tonyps · 06-11-2008, 01:02 PM

Jeff, I have had success with this using a thorough pre-wipe with acetone then using TiteBond III.....

Regards,

Tony ...

Mike Davis · 06-11-2008, 01:35 PM

I never heard of cumaru, got a picture of it?

DaveO · 06-11-2008, 06:05 PM

Originally Posted by Mike Davis

I never heard of cumaru, got a picture of it?

Cumaru is a great subsitute for Ipe , and often can cost less.
http://www.eastteak.com/products/fin...maru_data.html

http://www.rain-tree.com/cumaru.htm

http://www2.fpl.fs.fed.us/TechSheets...yxodorata.html

http://www.conradfp.com/cumaru-decking.shtml

Dave

MikeH · 06-11-2008, 06:12 PM

Originally Posted by charlie s

Jeff:

I have one experience with cumaru and it wasn't a pleasant one: a trip to the emergency room. I'll confess to not following correct safety procedures but what happened was when I was routing the edge of a glue up, the wood shattered, grabbed the router bit and jerked it into my hand that was holding the piece. Yes, I should have clamped the piece down and used both hands but I've never seen wood shatter like that. This wood has a tendency to splinter similar to hickory so be very careful when using a router on it. As far as glue goes, I'd look into using plastic resin glue, although I didn't and haven't heard of any issues with the piece I glued up.

Charlie

I have a piece of that cumaru and boy is it hard and heavy! I haven't done anything with it yet.

Jeff · 06-12-2008, 10:05 AM

Originally Posted by tonyps

Jeff, I have had success with this using a thorough pre-wipe with acetone then using TiteBond III.....

Regards,

Tony ...

That's helpful info. I was beginning to think that I'd have to use Gorilla Glue (polyurethane). I won't have many joints to glue and this project is not gonna be under a high stress/load condition.

Thanks.

Glennbear · 06-13-2008, 08:58 AM

Originally Posted by DaveO

Cumaru is a great subsitute for Ipe , and often can cost less.
http://www.eastteak.com/products/fin...maru_data.html

http://www.rain-tree.com/cumaru.htm

http://www2.fpl.fs.fed.us/TechSheets...yxodorata.html

http://www.conradfp.com/cumaru-decking.shtml

Dave

Thanks for the info Dave, all I needed to cross this off my list of species to use in projects. The LAST thing I need is to work with a wood that contains an anticoagulant blood thinning chemical

DaveO · 06-13-2008, 07:03 PM

Originally Posted by Glennbear

Thanks for the info Dave, all I needed to cross this off my list of species to use in projects. The LAST thing I need is to work with a wood that contains an anticoagulant blood thinning chemical

I think that refers more to the seed and bark than the dried lumber or dust of the lumber. I wouldn't not use it, if for that reasoning alone.

Dave

Kdub · 06-13-2008, 10:57 PM

I bought some cumaru tounge and groove flooring to make my benchtop with. amazon exotic hardwoods out of harrisburg has all kinds of, well exotic hard woods. the reason i wanted to use it was it's hardness. watch out for splinters. i just used liquid nail to fasten it to the already exisiting table top. Sorry i don't know much about the gluing, but it should make a great outdoor table. real pretty color, imo. make sure you sand the edges well.
kurt

Jeff · 06-14-2008, 08:51 AM

Originally Posted by DaveO

I think that refers more to the seed and bark than the dried lumber or dust of the lumber. I wouldn't not use it, if for that reasoning alone.

Dave

Your correct. The lethal dose in rats is 680 mg/kg so a 170 lb (abt 77 kg) human would have to INGEST about 52 g of pure coumarin. That's about 0.1 lb. of pure stuff. If the dust or wood contained as much as 10% coumarin (which it doesn't) you'd have to eat about 1 lb. of it. Happy munching, but be prudent.