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Forum topic by unclearthur posted 08-23-2019 11:28 PM 336 views 0 times favorited 13 replies Add to Favorites Watch
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unclearthur

266 posts in 2267 days


08-23-2019 11:28 PM

I recently bought a cheap globe, and I’d like to make a wooden stand for it, something like:

The glove is 12” diameter.

I’m trying to figure out the best way to make the curved piece that directly supports the globe. I could cut it out of a large piece on a bandsaw ….but I don’t think the grain direction would look very nice on it, and perhaps it wouldn’t be very strong either.

It seems to me the nicest way of doing this would be bending some strips of wood, but I’ve never done that before, have no special gear, no special woods or any idea if it is reasonable radius to achieve etc…...

Any thoughts on how to do it, or alternatives would be appreciated.

Thanks


13 replies so far

View Nubsnstubs's profile

Nubsnstubs

1612 posts in 2210 days


#1 posted 08-24-2019 01:48 AM

If it’s a 12” globe, I would get my compass set up for 12 1/4”OD. get a board 10” wide x 14” long. Find center on the 14” length. On the 10” side, mark 2” up from the bottom crossing the center line creating your start point for making the yoke? for the globe. Mark the 12 1/4” half circle, starting at the 2” mark, in this case, the inner diameter of the yoke. Whatever thickness you want the yoke to be, adjust the compass to allow for the thickness of the yoke. Save that dimension. Make the second mark for the outer diameter of the yoke.

When you have all marks done, use a square where the the circles intersect with the 2” line. That’s your start point for cutting. Take the wood to your band saw, and as carefully as possible, cut along the lines not deviating or wandering. Cut on both lines. Discard the thin strip.

Whatever you came up with on the difference between the inner and outer compass setting, you will need to cut strips that will make up that distance. Stay at or under 1/8” for the strips to be able to bend under clamp pressure.

If you want a 3/4” wide yoke, cut your strips from 7/8” material or wider. Cut the length about 14-16” long. The half circle jigs should be the same thickness or pretty close. Glue it up, using 3 clamps, clamp from the center, and draw the inner circle into the outer circle. If you cut the lines cleanly, the jig will pretty much self center as you are drawing it together.. Twenty four hours later, release it from the clamps, strike it on a table surface a couple times. If it doesn’t come apart, you did good…...... Wood is your choice, but stay away from well figured woods. ........... Jerry (in Tucson)

-- Jerry (in Tucson) www.woodturnerstools.com

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Lazyman

3873 posts in 1867 days


#2 posted 08-24-2019 02:07 AM

I’ve made a couple of projects with steam bent parts. I just used a wallpaper steamer and a 6” metal duct for the steam chamber. The biggest problem is dealing with spring back. No matter what you do, you will get some spring back so you have account for that in the design. A glue lamination with thins strips requires less equipment and spring back is usually less but you will still have some.

Another option would be to glue up multiple straight segments with angled bridle joints to form a rough arc and then cut the final semi circle bracket on the bandsaw.

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

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rcs47

210 posts in 3609 days


#3 posted 08-24-2019 02:59 AM

Jerry described the bent lam process. Here is an example of the process:

https://www.lumberjocks.com/rcs47/blog/24554

Remember, you need a glue that will hold the form/shape. Polyurethane and epoxy are two options. Normal white & yellow wood glues will not hold the shape over time.

Good luck,

-- Doug - As my Dad taught me, you're not a cabinet maker until you can hide your mistakes.

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unclearthur

266 posts in 2267 days


#4 posted 08-24-2019 03:27 AM

Wow, thanks all, thats very helpful. Great explanation Jerry. I’ve done small projects with splines sort of like that before, just on a much smaller scale, but I hadn’t made the mental connection with the curved “yolk”.

On the glue, I have the West System 105 epoxy .... would that be OK? I’ve mostly used it for filling cracks before? Curious, though, as to why normal (Titebond) glue won’t work well ….. its all long grain to long grain …?

View WoodenDreams's profile

WoodenDreams

707 posts in 390 days


#5 posted 08-24-2019 03:51 AM

+1 for rcs47, If you do use titebond glue, you could use 1/8 or less thickness til you build to the thickness your after, but possibly have the strips 1 1/2” to 2” wide for more glue surface, after shaped you could insert dowels with buttons for extra support and accent.

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MrUnix

7468 posts in 2679 days


#6 posted 08-24-2019 04:34 AM

On the glue, I have the “West System 105 epoxy…. would that be OK?
- unclearthur

West system works very well… I use it to laminate sailboat tillers. I also add 403 microfibers, as it is an excellent gap filler – but for a small project shaped like yours, you should be fine without any additional fillers.

Cheers,
Brad

-- Brad in FL - In Dog I trust... everything else is questionable

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unclearthur

266 posts in 2267 days


#7 posted 08-24-2019 05:10 AM

This is sort of a strange question, but how best to spread the epoxy over so much surface area?

ie – layering the strips with 100% glue coverage is a fair bit of surface area, and I would think you need 100% coverage or it might de-laminate. It would be easy to cover with white glue, just spreading out with a finger, but epoxy is sort of a different (and more expensive) animal …...

View Tony_S's profile

Tony_S

997 posts in 3563 days


#8 posted 08-24-2019 05:40 AM



Normal white & yellow wood glues will not hold the shape over time.
- rcs47

Damn….ya mean I’ve been doing it wrong for nearly 30 years?

-- It is the mark of an educated mind to be able to entertain a thought without accepting it. Aristotle

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rcs47

210 posts in 3609 days


#9 posted 08-24-2019 01:03 PM

Tony, I was going by the research I did before I started doing bent lam. It said white/yellow glues joints will slip over time, changing the shape.

I’m happy to learn from those that have more experience than I do.

-- Doug - As my Dad taught me, you're not a cabinet maker until you can hide your mistakes.

View Nubsnstubs's profile

Nubsnstubs

1612 posts in 2210 days


#10 posted 08-24-2019 01:40 PM

Normal white & yellow wood glues will not hold the shape over time.
- rcs47

Damn….ya mean I ve been doing it wrong for nearly 30 years?

- Tony_S


I did my first bend with Titebond back in ‘78. It was a stool back that I set up for Rattan. I used 8 strips of 1/8×1 1/8” wide Red Oak. Today, that stool is just as sound as it was the day it came out of the jig and clamps.

The problems I had later was trying to use some 1/16” strips that I completely covered with glue. The water in it caused the wood to wrinkle, twist, and other things wood does when wet, but when clamping. it leveled out and looked pretty good when done.

Unclearthur, you could also do this using a circle 12 1/4” OD and use a good ratchet strap as your clamp. Forgot to mention that in my first reply. The only precision this way is the circle…......... Jerry (in Tucson)

-- Jerry (in Tucson) www.woodturnerstools.com

View Gene Howe's profile

Gene Howe

11757 posts in 3908 days


#11 posted 08-24-2019 01:55 PM

I’ve used TBII successfully for some fairly tight curves. I bring the maple laminates down to around 5/32. No steam required. Dry bent around the form and glued. Ended up with a 3/4” X 1” X 18” piece.

-- Gene 'The true soldier fights not because he hates what is in front of him, but because he loves what is behind him.' G. K. Chesterton

View Lazyman's profile

Lazyman

3873 posts in 1867 days


#12 posted 08-24-2019 05:33 PM

BTW, in general air dried wood is easier to bend if you can get it. The heat used in kiln drying sets the lignon and makes it stiffer, though the thinner the strips, the less of an issue it is. Kiln dried wood is also more likely to spring back.

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

View unclearthur's profile

unclearthur

266 posts in 2267 days


#13 posted 08-25-2019 06:18 PM

Seemed to work well enough:

Thanks all!

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