Tuesday, September 21, 2010

Tech Tip Tuesday

My students always seem to panic when they start working with epoxy because they're concerned that they're not going to have enough time to work with it and that it's going to cure before they're done.


Working with epoxy has nothing on steaming wood.

Steaming takes place fairly quickly - after you get the part out of the steam box you have a limited amount of time before the wood starts cooling to the point where it will not bend well anymore. Typically, something like 30 seconds to a minute depending on the type and thickness of wood that you're working with.

So, before you even begin, I recommend that you have your stock wet or pre-soaked, all of your clamps ready, your fixtures ready, any backing straps (either plastic or metal straps used to keep the grain from "running". You should be able to lay your hands on everything you need almost without thinking about it. Plan to have extra hands if you can and absolutely no interruptions. Think through what you're going to do and how you're going to do it before you start.

Put your stock in the steam box and wait the prescribed amount of time - about 15 minutes of steaming time per quarter inch of stock thickness. If it is a thick piece of stock, you may want to swab it with hot water during the steaming process to keep it from drying out and becoming brittle.

When the stock is ready, put your gloves on pull the stock out and start bending! Support the bend with your gloved hands or your strap to help it bend - almost like you're trying to stretch the wood around the bend and clamp or tack in place as is appropriate.


That wasn't so hard, was it? Now all you need to do is to let the parts cool and dry on your form until you're ready to use them!

Here are some pieces that I steamed this evening for the kayak's coaming and storage hatch rim and cover. The pictures aren't pretty, but you get the idea:

The inner rim of the gear hatch is two layers of 1/8" cherry and has been glued around the plywood hatch form after the earlier steaming session. I steamed another thinner layer of scrap - about 1/16" thick as a spacer and taped that around the inner rim as a spacer (so the cover will go on easily) and steamed and bent another two layers for the hatch cover. As I've said before, the goal is a hatch that looks a bit like a Shaker oval box cover.

The coaming is 5 layers of wide (1-1/4") cherry that are 1/8" thick. Two or more layers of narrower (1/2" wide) cherry will be used to form the cockpit rim after the wider portion of the rim has been glued up.

Both the coming and inner rim will have a series of holes drilled through them after finishing to allow them to be sewn into the skin. Obviously more to come, here.

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