bending gumwood

[saltytheseadog]

I'm wondering if anybody has experience with bending what is generically known as gumwood around here. Sorry I can't be more specific than that.Its generally used on commercial boats for guards, caprails ,hull sheathing ect.
I would like to place a cap of it on the stem of my 55 y.o. 6 tonner to repair the dings and for the new bolts to bear on rather than the punky iron sick holes that exist now.Its not a radical bend ,but is more than the 1inch thick piece will take i believe.

[Hughman]

Cut the gumwood into two or three strips and bolt them down. Glue if you want, but it doesn't sound critical.

[saltytheseadog]

thanks ,I don't think that will work as I would like to counterbore the carriage bolt heads into the gumwood cap a bit.

[ 10-23-2005, 11:46 PM: Message edited by: saltytheseadog ]

[Rick Tyler]

"Gumwood" is another name for a eucalyptus or liquid amber. I don't believe I've ever seen it in a hardwoods store either here in Washington or in California. I find *lots* of BC hits when I google on "boats gumwood," so it looks like traditional boat wood where you are. I found pictures of gumwood on these sites almost exclusively used for gunwales and other high-wear surfaces.

I've dealt with eucalypts in California and the species that were brought there are hard, tough, twisted, and split. They were imported to grow for railroad ties -- a use for which they were spectacularly unsuited.

I have zip experience using gumwood as lumber, but it is really tough stuff, and lots of other folks use it on boats.

I do know that we were having trouble with bending a 1x2 Douglas fir stick for the gunwale of a drift boat. We had a couple explode after being clamped on. We soaked the sticks for a couple of weeks in fresh water, clamped them in place wet, waited for another week, then unclamped them and allowed them to dry. They took a nice bend and we were able then to screw them in place. It took very little work, but a lot of days waiting. Douglas fir doesn't steam real well -- I don't know about gumwood -- and I don't know if the soaking trick would work either. Good luck.

Someone will likely pop around soon with a better answer.

[ 10-24-2005, 01:41 AM: Message edited by: Rick Tyler ]

[shamus]

If the 'gumwood' is Eucalyptus globulus, (blue gum) which has been extensively planted in Ca, then it bends quite well if steamed. Thousands of boats have been built here using it for bent frames. These trees however were grown in heavy bush and were slow grown. Grown in the open blue gum will grow quickly and may be less stable on account of this. It's tough and heavy stuff.

[formerlyknownasprince]

In the following photo you can see a couple of new Spotted Gum (a eucalyptus species) ribs - these were sistered - the vacant rib sports aft of there received full ribs. We had no problems at all bending these ribs after steaming for about an hour. From memory, they were 19mm thick and about 60mm wide - two per rib.

http://www.imagestation.com/picture/sraid99/p8a4e826fc76b323b6d1cd774c4fe8fee/f9e99ff4.jpg

We used this automotive steam cleaner to power a steam tube:

http://www.imagestation.com/picture/sraid101/p2d9f0043aeb1c0aa3384a9df0c427418/f9dff088.jpg

The steam tube was simply a length of 6" PVC plumbing pipe, through which we inserted some wires to support the timber. It was wrapped in Armaflex tape insulation ('cause I had some under the house!) The PVC pipe got a tad flexible while hot - so I wouldn't recommend moving it.

My wife donned the welders gloves and got the job of pulling the steamed ribs and passing them through the porthole.

We did that job a couple of years back. Not one of the dozen ribs has split or had any other problem.
http://www.imagestation.com/picture/sraid101/p02c6ebbf8912b3337f3925357d0e4e7c/f9dff0a3.jpg

I'd be happy to loan you the steambox - but I'm sure you could make one for $50.

Ian

[saltytheseadog]

Thanks everyone for the advice.I'm not sure if were talking about the same species of wood but I'm encouraged by the advice from down under and will try steaming the wood. Thanks Ian for the offer of your steamer,I have one here.