Hardware vs Steam Box

[bassman1956]

I have my grab rails all shaped, location and mounting holes drilled, etc. But, there's about 1/2" of bow, and 1/4" elevation change, that I'd rather remove by steaming and fitting than by just stressing it into place with the mounting screws.

I'm looking at using hanger bolts / screws, which are wood threads on one end, machine screws on the other. This would give me positive locating pegs to help locate the screw holes when handling the hot wood and bending it to shape. I can always replace the hardware after steam fitting.

Question: Any problem with the wood if I have these screws already threaded into the grab rail bottoms when I steam them? The grabs are white oak.

[SabreKai]

I can't think of any problem with your plan, other than perhaps rusting if the fasteners are MS and not stainless. Any flexing as you do the installation will be along the thinner part of the hand rail, the bases being much shorter in length will pretty much stay straight.

Sabre

[bassman1956]

Thanks. Those are my thoughts too. Hardware will be SS.

[cburger]

Why not make a jig then clamp the the handrails to the jig after steaming?

[bassman1956]

Originally Posted by cburger

Why not make a jig then clamp the the handrails to the jig after steaming?

A lot of extra work to make 2 jigs that match my cabin roof. And I'll still need a way to help locate the mounts. So Plan A is to just use the taped & marked outlines and 3 sets of hands. Plan B is to use Plan A, but add the benefit of positive location of the mounting holes by using screws somehow. Steamed wood doesn't stay flexible for long. Locating pins for the holes would help. Lots.

[Tellie]

Steaming is always a lot of fun. I'd sure like to see a few pics posted here bassman of your methods, procedure and progress as you go along.

[GorillaToast]

Originally Posted by cburger

Why not make a jig then clamp the the handrails to the jig after steaming?

I tried that with my tiller, which being ash, is supposed to take a bend quite well. Maybe 5 days in the jig wasn't long enough, 'cause now I've got the same straight tiller I had before steaming.

BTW, I found that antique-store pipe organ pipes (long wooden boxes) make great steamers. I got my 7 footer for $3.95.

[GorillaToast]

Picture of aforementioned organ pipe steam box:

[boatsmith]

If your grab rails are teak you won't gain much if ant thing by steaming them. Teak is rated a 3 out of 100 as far as suitability for steaming. The oil in the wood keeps the steam from softening the cell walls which is what enables the wood to bend. I have steamed small oak ribs for canoes and 5" thick 40" planks for ships. I have also tried to steam teak for curved covering boards. I wasted a lot of good teak ion this manner.

[SabreKai]

If per chance you do decide to jig up the parts, then make sure that the jig puts a bit more curve in than you will need. The wood will relax some even after steamed to a jig. Don't ask me how much, its a learning experience. I know this because I once made up 31 pairs of stub ribs for my last wooden boat. I didn't have a steam box so I put a couple of bricks into a 5 gallon pail, filled it with water to the top of the bricks and set the ribs in vertically. Covered the top with a towel and put the thing on my kitchen stove. Once steamed/boiled for a while, about an hour per square inch (I think, it was a long time ago), I pulled out the stubs a couple at a time and bent them in a jig made with a hydraulic jack and some steel bars. It worked quite well but took a while to get the degree of pressure down pat.

Sabre

[bassman1956]

Thanks all.

My thoughts are thus:
Three pair of hands pull the rails out and put them in place instantly. (Steam box will be in the garage with the boat.) Then, if I have the hanger screws installed (the current plan), someone quickly runs up nuts and fender washers from inside. Then we walk away overnight. Next day or later, remove the hardware prior to final finishing, mount with bedding compound. If the hanger screws look iffy, I'll replace them too.