Holding - double stick tape/hot melt glue/ what else?

[Roger Chandler]

Just wanting to pick some brain energy here from the group. I have an emerging bowl demo this Saturday at one of the clubs here in Virginia. I have done several of them now, but am a bit dissatisfied with the holding issue. I have used hot melt glue quite successfully, but it is a bear to clean up well without some tearing of the wood, and having to use a chisel to part the thing off a backer board is a pain.

I tried double stick tape that is called "woodturners tape" that I got from WoodCraft. I am not too keen on that alone, as I don't trust the hold all that much, so on my last practice bowl I used a bit of both.

Any of you turners have ideas on being able to hold securely without tailstock pressure at around 600 rpm? The bowl I will demo starts out at 5" as a cube, then is turned down halfway to a 4" diameter. I need to be able to mount to a backer board held in the chuck, and then remove when the inside of the bowl is turned. The outside is turned being held in the chuck, so that is not an issue.
Any ideas would be deeply appreciated!

[Prashun Patel]

I know people use tape and hot melt glue. But I'm not comfortable with either. I prefer wood glue for glue blocks, and a good day for it to dry.

I part off the block, so tear-out isn't an issue.

[John K Jordan]

...
I tried double stick tape that is called "woodturners tape" that I got from WoodCraft. I am not too keen on that alone, as I don't trust the hold all that much, so on my last practice bowl I used a bit of both.

Not only does the good double-sided tape hold well, when applied the way we do it is difficult to remove. A friend and I use it to hold metals for machining, pressing together and holding for a few minutes. We found the tape released best when forced apart with a narrow wedge, but VERY slowly. (took 10-15 minutes)

A turner I know used it on a bunch of bowls 12-16" in diameter, rough turned from a block and finish turned later. He first flattened and sanded a big enough spot on the chunk of wood to match up with a faceplate. He cleaned the faceplate. He put one layer of tape on the face plate and another layer on the bowl blank. Crossing these, he pressed them together then applied pressure with the tailstock and left overnight. The holding power is amazing.

The last time I did an emerging bowl I used just one layer of the good woodturners double-sided tape. I simply stuck it a flattened piece of wood held in a chuck and applied pressure for a few minutes with the tailstock. (the piece is out of balance when halved for the hollowing but the weight is much less) Turned just fine about 1200 RPM. It would probably stick even better on a faceplate. Anyone remember faceplates?

I don't trust hot-melt glue except for light-weight things.

If doing this demo I'd experiment at home ahead of time by sticking down an out-of-balance block and hollow a bit while spinning to about three times the intended speed. (being careful where I stood and what I wore on my face.)

JKJ

[Don Frank]

Roger,
Hot glue becomes brittle when frozen. You can chip it off very easily if you have the time to put a piece in the freezer for an hour or so. I realize this answer won't help for the purpose of a demo but might be helpful in your own shop on future projects. If you drop a glue stick on the floor after it is frozen it will shatter. You might test putting a piece glued with hot glue on a quart ziplock bag of ice for about five minutes and see if that will do the trick .

[Roger Chandler]

Some nice ideas here. I went to our local hardware and picked up some “heavy duty” double stick tape, and I think I’m going to try John’s advice, then add a wrap or two of strapping tape to the square end of the emerging bowl blank and tape it tight to the square backer board. At least I won’t have to scrape all that hot melt glue off!

[Tom Giacomo]

If using hot glue I take an eye dropper and put a few drops of denatured alcohol on the seam where the wood and glue meet and in a couple minutes they will part.

[Roger Chandler]

If using hot glue I take an eye dropper and put a few drops of denatured alcohol on the seam where the wood and glue meet and in a couple minutes they will part.

Thanks for this tip, Tom. I’ll have to give this a try.

[JohnC Lucas]

cloth backed double stick tape is remarkable stuff. Holds like crazy. Apply the tape, put the 2 parts together and then clamp them for 30 seconds or so. You will get a very strong bond. To get the parts apart I try one of two methods. I have a very thin butcher knife that I have dulled the edge. You can gently tap that through the joint and it breaks it. If this fails I use a Garrot. Well actually it's a think guitar string with 2 wooden handles that I use to burn lines in spindles. I have found that you can sort of saw through hot glue or tape joints and break them free. The advantage of the tape of glue is you can usually peel the tape off after separating the joint. Harder to do with hot glue.

[Roger Chandler]

cloth backed double stick tape is remarkable stuff. Holds like crazy. Apply the tape, put the 2 parts together and then clamp them for 30 seconds or so. You will get a very strong bond. To get the parts apart I try one of two methods. I have a very thin butcher knife that I have dulled the edge. You can gently tap that through the joint and it breaks it. If this fails I use a Garrot. Well actually it's a think guitar string with 2 wooden handles that I use to burn lines in spindles. I have found that you can sort of saw through hot glue or tape joints and break them free. The advantage of the tape of glue is you can usually peel the tape off after separating the joint. Harder to do with hot glue.

Thanks for this John!

[Bruce Schoenleber]

That woodturners tape from woodcraft holds very well. Just clamp it for a minute.

[Dennis Ford]

Possibly not suitable for your demo but hot melt glue can be very strong IF you can keep it hot until the parts are pressed together. Applying hot glue to a heated face-plate and then pressing the wood on will make a strong connection (after the face-plate cools).

[Brice Rogers]

You've already got good advice. A few more thoughts:
1. Paint thinner will dissolve (albeit not super fast) residual hot melt left on the piece.
2. If you have hot melted to a sacrificial block of wood (no metal), you can heat up in the microwave to soften the glue and then scrap most of it off with a chisel or pocket knife. I've also used a heat gun (< $15 at HF) to soften hot melt.
3. If I'm using something like an aggressive double back tape with re-inforcing (I have a roll with fiberglass re-inforcing) I will often add a "belt to the suspenders" - - that is, I'll either add filament tape or packer's stretch wrap to ensure that even if the tape lets go that it won't go flying.