marshall head cab question

[scole]

what is the radius of the outside edge? it seems to be offset.

[WMThompson]

I traced the radius on the rear top corner on a 100w reissue, and
it was 7/8" or 22mm.
In one of my books on Marshall, it states a 22mm radius on a newer amp, so
that is all the info I have gained so far.
Please let me know what you can come up with.
Good luck
WT

[scole]

crusty over at weber says its 1 inch, with 1/2 in thick material. that seems thin to me. to my eyes it looks like the radius is larger than the thickness of the material creating an eliptical shape rather than a perfect radius like on fenders.

[WMThompson]

Yeah-I know what you mean by that larger radius on a thinner board!
I'll bet it's 15mm birch ply (5/8")
with a 22mm (7/8")radius.
I'm pretty sure the front panel is 12mm (1/2").
Try this,
go to a music store that sells reissues, and take your tape
measure.
Maybe with some help from others we can figure it out!
Keep me posted
WT
ps
think about the larger radius on a tweed backpanel vent hole,
I pulled that off successfully, I think I could do it on a Marshall cab edge
radius if
I could only be sure it was correct.

[scole]

at this point it looks like 5/8, 13ply baltic birch is the way to go. ill probably go with the 7/8 radius roundover bit since its about 75 dollars, a 1 inch is 125 dollars. most of the cab builders say there marshall cabs are made from 13 ply bb. after looking at a lot af pics on e bay i have to say they look 5/8 thick to me. i drew up a 3d model on my cad program and it looks exactly the same.

[WMThompson]

Scott,
Sounds like we're in agreement, .
Do you have dimensions on everything?
Maybe we could compare notes.
Too bad you live so far away, you could borrow my 7/8" router bit.
keep me posted!

WT

[Bruce / Mission Amps]

When building my own cabinets in our old wood shop, I always used a standard table top, thumb-nail bit in my 1/2" colleted, table top router for doing this... set the depth so the bead part of the cut does not hit the wood.
Just look "thumb nail bit" up and you'll easily figure out how to use it to get great looking round over that is not a 1/2", 3/4" or 1". Way better looking.

[scole]

i saw those table top bits and thought that would be the way to go, they are less expensive too.

[scole]

the next question is how to join the pieces. do i use finger joint, lock joint?. the guys over at wood central say to 45 the joint and glue, no fasteners.

[WMThompson]

Fender and Marshall both used 1/4" box joints.
That's what I use on mine, I wouldn't use any less than 1/2"
box joint.
The thumbnail bit looks good for a custom cab, but I would have to compare
really closely if I were to use one to recreate a Marshall cab, but I'm just picky about details.
WT

[Bruce / Mission Amps]

Fender and Marshall both used 1/4" box joints.
That's what I use on mine, I wouldn't use any less than 1/2"
box joint.
The thumbnail bit looks good for a custom cab, but I would have to compare
really closely if I were to use one to recreate a Marshall cab, but I'm just picky about details.
WTThere are different profiles to choose from.
I use to have our drawer building company build a couple dozen, blank cabinet carcasses out of 19mm Baltic Birch with std 5/16" or 3/8" pin and tail... exactly like a big ass drawer, then I would face them and or cleat to taste and round them over with the thumb nail bit as I wanted. Very simple and super fast.