Hexagon Pioneer B20FU20 Enclosure

[MJL21193]

Originally posted by John L


I would think this to be far easier for a person to turn on a lathe. And if the two pieces don't exactly fit with the same diameter, I could use a belt sander and finish the outside by hand. Then I can fill in any blanks, if any, and paint the finished product.

What do you think of that idea?

Yes, that works if you have access to a lathe (which I assumed you didn't).
Would you be using MDF or solid wood for the turning? Either is possible, with the MDF being easier to cut on the lathe and more dimensionally stable

I think I'd like it better if it were stepped, with just the widest ring rounded. It's your creation though.
Happy new year.

[John L]

You know, if worse comes to worse, I could indeed step it all the way around. In the end, it would most likely deflect the sound waves well. It would not look as nice as a finely flowing and polished horn though.

I had thought I would go ahead with the same material throughout, which is cabinet grade plywood. I even used that for the base.

Oh, I forgot, I can even use the spare pieces of plywood that I get from making my circular cuts with the router. I forgot about that way to use scraps. What is wrong with me.

[MJL21193]

Originally posted by John L
You know, if worse comes to worse, I could indeed step it all the way around.

Oh, I forgot, I can even use the spare pieces of plywood that I get from making my circular cuts with the router. I forgot about that way to use scraps. What is wrong with me.

Or, while turning, you cound cut in some "steps". Maybe just a few near the middle.

That plywood is poplar veneer core? Could be a finishing challenge as this core will soak up a lot of primer.

[John L]

Ahh, but I don't have that problem because I use shellac for a sealer. Obviously you are not a user of shellac. Shellac is the ultimate sealer, or finisher that is available. You even eat shellac when you eat M&Ms.

The only real limitation with it is that water and alcohol tend to ruin it's finish if left there for an extended amount of time. Table tops would work best if finished in a poly finish, or shellac with a glass top.

I always seal my wood with shellac before doing anything to it. It stores very well in flakes, and is very inexpensive to mix and apply. I simply cannot sing it's praises loud enough. And anyone who knows finishing will tell you the same thing.

Once I have sealed the wood in shellac, it will take any finish and take it well.

[MJL21193]

Originally posted by John L
Ahh, but I don't have that problem because I use shellac for a sealer. Obviously you are not a user of shellac. Shellac is the ultimate sealer, or finisher that is available.

And anyone who knows finishing will tell you the same thing.

I used to like shellac, in my youth. Shellac is a decent sealer, but it has limitations. You can't use it as a sealer for a polyurethane finish.

Speaking of polyurethane, that is the real ultimate sealer. It's solvent stable, meaning it will not separate when applied to a very absorbent substrate like the edge of MDF (or that poplar core ply). When it cures (it cures, it doesn't dry like shellac), it's completely inert, and there isn't anything that you can't overcoat it with.

[John L]

Originally posted by MJL21193


I used to like shellac, in my youth. Shellac is a decent sealer, but it has limitations. You can't use it as a sealer for a polyurethane finish.

But that is only partially true. You are thinking about waxed shellac in it's natural form. Dewaxed shellac has none of those problems.

I have never used shellac with wax, so I don't know how it works, or doesn't work. I only use dewaxed shellac. The dewaxed variety will work on anything to the best of my knowledge. I have never had any problems with it.

Another thing, all finishes have their limitations and poly finishes are no exceptions. if the surface is damaged, you cannot spot repair it. You have to take the entire surface down and start all over.

If shellac is damaged, all you have to do is either sand away the damage, using wet sandpaper, or sandpaper and denatured alcohol. Then once the damage is gone, you can recover the damaged area with another coat of shellac, and it will blend in with the rest of the finish.

[MJL21193]

Originally posted by John L


But that is only partially true. You are thinking about waxed shellac in it's natural form. Dewaxed shellac has none of those problems.

If shellac is damaged, all you have to do is either sand away the damage, using wet sandpaper, or sandpaper and denatured alcohol. Then once the damage is gone, you can recover the damaged area with another coat of shellac, and it will blend in with the rest of the finish.

Hi John,
Yes, it's the wax content that affects adhesion. This is a natural part of the shellac though, and it's removal diminishes it's quality.

Shellac can make a beautiful finish on a piece that will not see much abuse. It should be protected with wax though. I've done the classic French polish on a few things, but to maintain the beauty, it needs constant maintenance.

A point well made about repair being easier with the shellac finish.
There are many ways of fixing damage to pieces done with modern finishes though, such as coloured wax sticks for filling dents that will buff to a near perfect match.

I only use solvent based polyurethane as a sealer, either over solvent based stains (I don't use waterbased stains), or for MDF before priming it for paint.
Using the solvent based poly over the stain brings up the colour and highlights the grain.

I then use waterbased polyurethane clear finish on my wood projects and waterbased urethane paint for the painted projects. This is the best, most durable 1 part coating available IMHO.

[planet10]

Originally posted by Kensai
Having the tweeter sitting on something (like a length of dowel) that's sitting on the B20's pole piece (yes, with the dust caps removed)

[OzMikeH]

Make the top part out of plaster. cast it in sand.
scrub it with a nailbrush, then coat it with gloss black paint. that will secure any remaining sand and give it a pretty cool looking surface.

Use the first one as a pattern, then shove it into the sand to make 2 more so they will be identical.

[John L]

Originally posted by OzMikeH
Make the top part out of plaster. cast it in sand.
scrub it with a nailbrush, then coat it with gloss black paint. that will secure any remaining sand and give it a pretty cool looking surface.

Use the first one as a pattern, then shove it into the sand to make 2 more so they will be identical.

Oz, that's an excellent idea! I'm wondering why I didn't think of this earlier. But that is the purpose of a thread, such as this. Imput is great isn't it.

Thanks a lot Oz! You're a real Pal!