Suggestions for trimming burl veneer on exterior edged and inside curves?

[David Kuzdrall]

I am getting very close to the veneering stage of my speaker build and will be using imbuya burl for the front baffles. I am looking for advise on tools and techniques for safely trimming the burl veneer both on the perimeter of the baffle and on the inside of the speaker cutouts.

i have enough material to practice but once I put a speaker in the bag I want to ensure (as much as possible) that I get the desired result.

if it makes any difference I will be using unibond 800 and a vacuum press for the adhesion stage.

thanks in advance.

[Mike Henderson]

Getting good adhesion on the edges of a panel is always a challenge. What I do is make the panel oversize, then veneer and trim to size. I seem to have better success with the veneer "sticking" around the edges that way.

Otherwise, make sure you have sufficient glue around the edges and that the caul presses the edges really well. Even then, you should have a way to trim some of the edge, maybe with some profile that removes the real edge.

Mike

[Kevin Jenness]

A laminate trimmer with a sharp flush cut piloted bit. A down shear cutter can help suppress tearout. Climb cutting can help as well. Test cuts on a sample are never a bad idea.

Are you veneering the outside of an assembled speaker cabinet in a vacuum bag?

[johnny means]

when its really crucial, hand tools are your safest bet. Block plane, sanding block, scraper, veneer saw.

[Mike Henderson]

when its really crucial, hand tools are your safest bet. Block plane, sanding block, scraper, veneer saw.

+1 and go slow and careful.

Mike

[Rick Lizek]

It's much easier to make your panel oversized trim and bore after the veneering. Make a practice piece of cheap particle board to figure hole placement and angles, etc.

[Jim Tobias]

David,
You have gotten a lot of good advice about making the panel oversized and then cutting back to needed dimensions. That is the best way. But, if you have a need to trim back veneer after it is glued to a pre cut piece, I like the use a scalpel. I actually like the scalpel for most veneer delicate work(other than crosscutting several sheets at once...that's best done with veneer saw).
I just trimmed back a veneer face on some curved laminated legs today. Lay veneered side down and apply hand pressure to top of piece keeping veneer tight to tabletop. Follow shape with scalpel and it comes right off. I know you are using burl veneer, but if you have good glued edges, it won't matter. As others have said, getting a good glue bond at the edge of the veneer is crucial.
2nd picture shows veneer facing before trimming. 3rd picture shows after trimming back with scalpel and buffing edge with 400 grit sandpaper. See below

Jim
2013-02-27 14.10.05.jpg2013-02-27 14.00.25.jpg2013-02-27 13.51.00.jpg

[David Kuzdrall]

Thanks to all for the replies.

i wrestled with the idea of veneering everything first but due to some design criteria (mainly the curved sides) and the amount of handling required I opted for doing the veneering last.

do you have a good online source for the scalpel?

thx

[Mike Henderson]

Thanks to all for the replies.

i wrestled with the idea of veneering everything first but due to some design criteria (mainly the curved sides) and the amount of handling required I opted for doing the veneering last.

do you have a good online source for the scalpel?

thx

You can buy scalpels, both handles and blades, on eBay. There are several blade configurations so make sure you get what you want. Personally, I prefer a different kind of knife because I find scalpels to be a bit too flexible. I like the Japanese woodworking knives, such as this one. They come in left and right hand and you really need one of each. You have to sharpen the Japanese knives, while you can throw away the scalpel blade and replace it.

Mike

[Jim Tobias]

David,
Below are the two links where I purchased the scalpel and blades. They are from United Kingdom but I believe that must be where Swanson is located as I could only find them there. it only took a few days to get them. As Mike mentioned, there are a variety of blade types. I've found the 10A to work best for me. I have found that the slight flex in the blades only becomes a problem when I get in a big hurry and start putting too much pressure on the blade. If I just put a little pressure on it and slice down the line a couple of times, it cuts clean. And when it gets dull on the tip, I can drag it across a diamond hone twice and get more mileage before throwing it away.

Jim

http://www.ebay.com/itm/scalpel-hand...item2a185f81be

http://www.ebay.com/sch/i.html?_trks...at=0&_from=R40

[David Kuzdrall]

David,
Below are the two links where I purchased the scalpel and blades. They are from United Kingdom but I believe that must be where Swanson is located as I could only find them there. it only took a few days to get them. As Mike mentioned, there are a variety of blade types. I've found the 10A to work best for me. I have found that the slight flex in the blades only becomes a problem when I get in a big hurry and start putting too much pressure on the blade. If I just put a little pressure on it and slice down the line a couple of times, it cuts clean. And when it gets dull on the tip, I can drag it across a diamond hone twice and get more mileage before throwing it away.

Jim

http://www.ebay.com/itm/scalpel-hand...item2a185f81be

http://www.ebay.com/sch/i.html?_trks...at=0&_from=R40

not having any experience with scalpels I have to ask...are these fundamentally different then the exacto blades that I see at hobby shops?

thx

[Mel Fulks]

Interesting question on the scalpels ,I used to wonder about that too. My former father in law was a surgeon and gave me some blades,they are very much like like xacto stuff. He was a proctologist ,brain surgeons might use something different.

[Homer Faucett]

not having any experience with scalpels I have to ask...are these fundamentally different then the exacto blades that I see at hobby shops?

thx

IME, scalpel blades are far superior to X-acto blades. They are stiffer and sharper than X-acto blades, and you can get them in a variety of different shapes and contours. The scalpel handle I use has two pins that pass through the base of the blades to lock it in. As has been said before, there are several types of scalpels and blades, so YMMV. My father is a dentist, so he gave me some excess blades and a handle. I don't remember what brand/etc.

For straight veneer cuts, I tend to use a brand new blade on a utility knife. For two sheets or less, I usually have as good luck with that as using a veneer saw. Sometimes, the blade wants to follow the grain if you're not careful about which direction you cut from. I use the scalpel for more precise cuts (inside corners, etc.).

[Jim Tobias]

David,
I do not have any research to point to (personal or otherwise) about which is sharper. I guess I'm thinking with the scalpel that I'm not shaving off wood(like a handplane), but rather I am cutting through wood (like a rip or crosscut). That being said, it seems like a thinner blade and blade edge/point would cut through with less resistance. Like when they advertise that a thinner saw blade cuts through a board with less horsepower because it is engaging less wood. Nothing scientific, just my thought and observations. Might be wrong, but they have worked well so far for me.

Jim