Bridge plate grain orientation

[wblock77]

I chipped out the plywood bridge plate from my Norlin era J45. I'm replacing with Rosewood. Trying to decide on the grain orientation. I don't think all the string holes should run with a single grain line but orienting with the top won't help with structural support. I vote diagonal. What say you?IMG_7770.jpg

[Rudy4]

I personally wouldn't use anything that has vertical grain for a bridge plate. I use flat sawn maple and simply run it perpendicular to the top plate grain orientation.

The top bracing looks so stout in your photo I doubt the bridge plate is going to have any effect on tone or volume if that's what your reason for replacement is.

[redir]

You may want to consider not making a giant bridge plate as in the original. It's a good opportunity to get a bridge plate that doesn't kill tone. Make it about 1/8th inch larger than the bridge fore and aft and taper the edges to zero. All a bridge plate needs to do is anchor the strings and maybe give some cross grain stiffness there but those old J45 huge plates were tone killers.

I go for rift sawn with grain lines at the end about 30-45 degrees with the long grain going across the grain of the top like Rudy said.

Nice clean removal BTW.

[wblock77]

Thanks for the good replies. Most helpful. The bridge plate was not the driver for the top removal. It was kind of like picking at a loose tile in your shower and the next think you know, you're re-tiling the whole bathroom. The binding was crumbling and falling off (tortoise shell). The neck also needed removed for a reset. While removing binding, I discovered a good number of kerf lining segments broken. I think I did that when I was fixing cracks on the top and was clamping them to close. The plate was kind of an afterthought of while I was in there....

[phavriluk]

That double-X boxing the bridge plate causes me to think that any rules-of-thumb about bridge plates in conventional l one-X bracing schemes can be put aside as irrelevant. The double-X is a whole 'nother critter which I think negates a lot of the reasoning behind optimized bridge plates on a single-X guitar. I think whatever OP chooses to do won't have much influence on acoustic performance.

I missed an important piece in my comment when I was addressing bridge plate size: Listen to Redir's advice, as mercy mentions, about grain orientation.

[mercy]

Listen to redir what he said about orientation is correct

[redir]

If it was my guitar too I would thin the bracing out tapering it from the high point in the middle down to the edge of the guitar and feather the very ends. Those guitars are over braced. I've made double X guitars before and they sounded great but they were not Gibson copies. The bracing was much much lighter.

There might be something to be said for keeping it original for vintage reasons but a lot of those guitars have been modified by reaching into the sound hole too. The finger braces are huge too and should be tapered on both ends and thinned out.

[phavriluk]

Well, this guitar will never be a example of preservation, more like 'salvation'. I like Redir's advice about cleaning up manufacturing shortcuts as long as the soundboard is so accessible.

[Alan Carruth]

What redir said, although I tend to go a little further out both fore and aft than he does.

I use double-X bracing in my guitars, and aside from the fact that the plate is cut off at both ends by bracing, instead of only one as on standard tops, the plate is the same. The 'job' of the plate is to keep the ball ends from chewing into the soft spruce of the top; and structural or acoustic functions are secondary IMO. keep the plate no bigger than it has to be while still extending it past the front and back edges of the bridge, and reduce the stiffness and weight of those edges by thinning it away as much as possible, and it will do it's job.

[wblock77]

Lots of food for thought for me. Thank you so very much. This guitar was in such bad condition that it would have take a couple thousand dollars with a luthier to bring it back. As you know, the Norlin's aren't worth very much. I picked it up at the salvage value price. Except for the bridge plate, I've been just working on the functional aspects. Unfortunately, the binding was really shot and was falling off and I can't get the tortoise shell like what was on there. Not anything remotely even close. Just fixing cracks and such. And plugging 4 nail holes on the sound board. Not sure what that was about but I'm sure there is a story. Also, there was a screw in a brace inside with some string dangling. I'd also like to know that story. Perhaps when the owner replaced the bridge with this one (actual picture of this guitar), he temporarily nailed something in so he could determine where the saddle should be slotted.
x.jpg

[wblock77]

Just in case you'd like to see the screw and guess what it was for. It was glued in as well.
IMG_7664.jpg