Kerfing.

[B7L|BL4Z3R 4]

So i have been reading on how to calculate the tuning on a box with a kerf. What is a common kerf radius? and how to you cut the wood to become that radius? google isnt really helping me out here. i know there is some extremely good carpenters here that might be able to help me out. how deep do i cute to wood to cause a certain radius. i would like all the input you guys have on kerfing to help me figure it out completely. Thank you.

[tyoung515 7]

you will have to cut it to paper thin, make a couple test cuts to figure it out, and for a 3" radius i use 11 cuts 1/3 in spaced. unless the box is huge or you have a really small port than this size should work well for you. dont forget to add 2-4 layers of glass and cloth over the front and i put a 45 behind it to add strength. hope this helps man!

[B7L|BL4Z3R 4]

thanks. how high do you put your saw? and i definitely planned on glassing it for strength.

[B7L|BL4Z3R 4]

ok let me see if i have the tuning right. if the box is 4.42824 cuft after displacement and i want it tuned to 32 hz. with a port that is 15.5 inches tall and a length of 22inches kerfed.

[tyoung515 7]

well its gana be just under 3/4 of an inch like cant really tell you the measurement paper thin lol

[mikey5472 16]

measure you're blade to 11/16" deep leaving about a 1/16 of an inch in the wood.

[B7L|BL4Z3R 4]

I asume that I need to be carefully when I bend it so it doesn't rip apart. Or is it still pretty strong. And how does the tuning look?

[mikey5472 16]

I asume that I need to be carefully when I bend it so it doesn't rip apart. Or is it still pretty strong. And how does the tuning look?

As for tuning im not sure but yes be careful when bending it. I think i read somewhere that when you do a kerf you add length to the port. Not sure how much or anything

Edited June 7, 2010 by mdizzle5472

[B7L|BL4Z3R 4]

Yeah I read you take your radius divide it in half and add that to your length. That's what i did up above.

[tyoung515 7]

tuning is good, and as i said 2 times do test cuts to find depth, 1/16th is not deep enough to make the bend, more around the lines of 1/32, and yes be very careful when bending and moving till glassed what i do is screw a guide on each end to hold it at a perfect 45 degree angle then glass/sand/glass/sand/bondo/sand/bondo/sand lol you get the idea but keep the guide on there till your ready to put the 45 on it

[B7L|BL4Z3R 4]

thanks guys. any more input and advice would be great.

[antonmiller 8]

i left just under 1/32" of "paper" left when kerfing mine. IIRC 3/8" spacing, 14 cuts to achieve 2.5" radius with plenty of room for resin behind it.

[B7L|BL4Z3R 4]

How far apart?

[antonmiller 8]

i left just under 1/32" of "paper" left when kerfing mine. IIRC 3/8" spacing, 14 cuts to achieve 2.5" radius with plenty of room for resin behind it.

[Jay-C76 333]

When I do flares,

Set the saw at 11/16" deep and space the cut every 3/8" apart.

1/16 of material is plenty to form a perfect flare. any deeper and

and you can snap the flare when forming.

(trust me I've done my fair share of flared ports)

A 3" radius is generally easy to work with.

Also drill holes 5/8" deep, staggered on the lines.

This will help the Poly Resin to fill the voids in the kerfs better

by allowing air bubbles to escape an rise to the surface.

If the cuts are too shallow you'll wind up with splitting along the kerf lines on your finished side.

Also use a sacrificial piece of wood clamped to the bottom of the piece you are cutting the kerfs on.

This will keep the panel flat and insure the depths of each cut are true and consistent.

Oh, and like mentioned above PRACTICE first!!!

( I should do a complete write up on this, lately I've been seeing a ton of Q's about this)

[mikey5472 16]

When I do flares,

Set the saw at 11/16" deep and space the cut every 3/8" apart.

1/16 of material is plenty to form a perfect flare. any deeper and

and you can snap the flare when forming.

(trust me I've done my fair share of flared ports)

A 3" radius is generally easy to work with.

Also drill holes 5/8" deep, staggered on the lines.

This will help the Poly Resin to fill the voids in the kerfs better

by allowing air bubbles to escape an rise to the surface.

If the cuts are too shallow you'll wind up with splitting along the kerf lines on your finished side.

Also use a sacrificial piece of wood clamped to the bottom of the piece you are cutting the kerfs on.

This will keep the panel flat and insure the depths of each cut are true and consistent.

Oh, and like mentioned above PRACTICE first!!!

( I should do a complete write up on this, lately I've been seeing a ton of Q's about this)

You really should though. I bet ssa would pin it in the spl/sq fab section!!

[Jay-C76 333]

You really should though. I bet ssa would pin it in the spl/sq fab section!!

I'll work on it and post on up. It should be pretty cut and dry, and I'll add pics too.

Heck it has to at least help somebody who want to try it.

It's not an easy thing to master, but with good directions and practice, it should be easy to get down.

[B7L|BL4Z3R 4]

holy crap. thanks man. that really helped. i had a general idea but the pictures really make it happen. i think i have it pretty down. doesnt look to difficult. now my only problem would be if im going to kerf both sides or just one.. one would be easier but both would look way better imo. thanks for all the help guys. i did some practicing yesterday and it turned out well. im going to try it a few more times then take a crack at it.

[Thumpper 266]

When I do flares,

Set the saw at 11/16" deep and space the cut every 3/8" apart.

1/16 of material is plenty to form a perfect flare. any deeper and

and you can snap the flare when forming.

(trust me I've done my fair share of flared ports)

A 3" radius is generally easy to work with.

Also drill holes 5/8" deep, staggered on the lines.

This will help the Poly Resin to fill the voids in the kerfs better

by allowing air bubbles to escape an rise to the surface.

( I should do a complete write up on this, lately I've been seeing a ton of Q's about this)

something I wish I would have never showed pics of

[B7L|BL4Z3R 4]

When I do flares,

Set the saw at 11/16" deep and space the cut every 3/8" apart.

1/16 of material is plenty to form a perfect flare. any deeper and

and you can snap the flare when forming.

(trust me I've done my fair share of flared ports)

A 3" radius is generally easy to work with.

Also drill holes 5/8" deep, staggered on the lines.

This will help the Poly Resin to fill the voids in the kerfs better

by allowing air bubbles to escape an rise to the surface.

( I should do a complete write up on this, lately I've been seeing a ton of Q's about this)

something I wish I would have never showed pics of

what do you mean? like giving away your tricks?

[Jay-C76 333]

something I wish I would have never showed pics of

Awwww.......

The way you work with wood is an art.

Ten thousand people could try this and never perfect it the way you have.

Plus, it encourages new designs to be thought of.

Anyone can build a box.....It takes a master to create a masterpiece.

And I would be proud if people wanted to "copy" my designs,

It would only mean that I'm doing something people actually like!

You're like the Yoda of enclosure designs !!!

All the rest of us aspire to do the great work that you do, or even to just come close.

[wutang512 3]

Is kerfing for looks or does it actually do something?

[Sir-Lancelot 216]

Is kerfing for looks or does it actually do something?

Helps with port noise and it just looks badass.

[Jay-C76 333]

Is kerfing for looks or does it actually do something?

Helps with port noise and it just looks badass.

Oh yeah, throw some high gloss lacquer on there as it looks almost plastic...

[jlftn 11]

keep in mind the basic trig equation, length of an arc (s) = radius of curvature ® * degree through which arc curves (in radians NOT degrees)

so for a 3" radius curve, for 90 degree bend (but convert to radians by multiplying by pi/180),

arc length (s) = 3" * [ 90 * (pi/180) ]

s = 3" * 1.5707 = 4.7115"

So basically just add that length in your calculations to find the total length of the piece you need to cut then kerf away!