Advice on bending wood purfling strips...

[Florida Jim]

So, ...I plan to put curly Koa wood purfling around my 5 string bass. Most of the curves are typically gradual, but there are some fairly tight bends also. The Stewart-Macdonald site says to lightly moisten the piece and work it against a hot pipe type bender. I practiced with using the lower shaft area on a soldering iron, and so far, everything results in the wood cracking, or breaking in two. OK, so please, can I get some advice from people who are good at this!! How hot, how wet, how long to heat it before trying , etc. Thanks! This seems easy, but these Koa strips are not cheap.

[John Wentzien]

Here's a start
http://www.ultimatehandyman.co.uk/WO...NDING_WOOD.htm
Do a search on "steam bending"

[Florida Jim]

Thanks John! Any other words of wisdom out there?

[Georynn]

From the few times I've had to bend something wooden, it sounds like you are heating the wood to fast over too small an area.
With something as thin as purfling, I would suggest you heat it more slowly, and use something other than a soldering iron.

You only want to gently heat and steam the wood, not cook it, try heating it under a damp cloth with a household clothes iron. Heat it for two or three minutes (or longer) until you feel it soften. It should stay soft enough to bend a length, then glue it in place. Wrap tightly with a rubber band or some type of string, lather, rinse, repeat, but S L O W L Y.

[Nelson Guitars]

As with anything practice makes perfect.

You can make a hot pipe from almost any pipe and a propane torch. You want to make it just hot enough so that water dripped on the surface just dances off and no more. The torch should be going hissssss and not HISSSSSS! A large diameter pipe will allow enough surface contact for you to get the wood hot over a large enough area to work right.

Just use a little water to keep from scorching. You don't need to soak it for hours. Just spritz with distilled water. Depending on the mineral content of water in your area the water can actually stain the wood.

Put the wood on the pipe and work it back and forth. While heating it up you can flip it over a couple of times to warm it evenly. Keep pressing with about 50% of the pressure it would take to break it. Then, all of a sudden, the wood will give a little. Patience grasshopper. You are close. Let it heat a little more and it will plasticize and almost bend itself. Guide it to the shape you want and don't force it. Take it off the pipe for only a little bit and it will harden again quickly.

Good luck.

Greg N

[hoytbasses]

greg is on the money! It's all about feel... you just have to practice. knowing when the pipe is too hot vs too cold is an intuition thing that can only be done with practice. Be careful: bending wood is VERY addicting

buy yourself some less fancy binding to practice on so you don't trash your very expensive binding. It also helps sometimes to thin out the binding at the point of a really sharp radius do this with 80 grit paper wrapped around a block.

I also keep the guitar close by so I can use blue painters' tape to attach it to the guitar's shape while it dries overnight

to attach the binding, I get bicycle inner tubes and cut them into 3/8-1/2" strips. 1-2 inner tubes will suffice. you use these giant rubber bands to hold the binding in place while glue dries. it does a better job than masking tape for holding binding tightly in the channel. you glue a little bit, wrap a little bit , starting at opposite ends (assuming you've dry fit and trimmed the binding) and work your way around.

have fun!

[erikbojerik]

How thick is your koa? You should have it just thick enough to leave a little margin for finish-sanding, and no more (if it's going to be used as the outer-most binding).

If all else fails....SuperSoft II. You spritz it on, wait a day or two, then steam-bend it.

SuperSoft II

[Florida Jim]

Thanks for the help! The bindings are .080" thick and .25" wide with a thin black/koa/black lamination on them. I'll heat up the wood completely and put slow pressure as you suggested.