I built a spreadsheet that will calculate the board feet needed for new
projects by putting in each piece and its dimensions. I have built it with a
"waste factor" for jointing sites, kerfs, exact widths I need not available
when selecting my wood. Since I am a newbie, and don't have enough
experience yet to know, I was wondering if anyone has a % they use to add
for waste when you do your own calculations.
Thanks
Craig Orput
Cave Creek AZ
You can get close by figuring around 20%, providing you've done the project
before and the methods are familiar to you. If your new to the methods
required, 30% may not be out of line.
--
www.e-woodshop.net
Last update: 9/21/03
"Pops" wrote in message
>
>I was wondering if anyone has a % they use to add
> for waste when you do your own calculations.
Pops wrote:
> I built a spreadsheet that will calculate the board feet needed for new
> projects by putting in each piece and its dimensions. I have built it with a
> "waste factor" for jointing sites, kerfs, exact widths I need not available
> when selecting my wood. Since I am a newbie, and don't have enough
> experience yet to know, I was wondering if anyone has a % they use to add
> for waste when you do your own calculations.
As a hobbyist I used to figure about 100% waste, but my wife caught on pretty
quickly. Now I can only get away with about 30%.
--
Jack Novak
Buffalo, NY - USA
(Remove "SPAM" from email address to reply)
Now, of course, you realize that the "clear cuttings" are of various
dimensions?
Bid with +25%, keep the excess, you'll need it to fill in where you screw up
on the next job.
"Roy Smith" <[email protected]> wrote in message
news:[email protected]...
>
> Once you realize that, it's not quite so mysterious.
"Pops" <[email protected]> wrote in message news:<[email protected]>...
> I built a spreadsheet that will calculate the board feet needed for new
> projects by putting in each piece and its dimensions. I have built it with a
> "waste factor" for jointing sites, kerfs, exact widths I need not available
> when selecting my wood. Since I am a newbie, and don't have enough
> experience yet to know, I was wondering if anyone has a % they use to add
> for waste when you do your own calculations.
>
> Thanks
> Craig Orput
> Cave Creek AZ
Craig, I am getting fed up with all you computer-types that are using
shortcuts like your stupid spreadsheet program to get out of doing
old-fashioned hard work. Take your spreadsheet and shove it where the
sun don't shine!
"Life aint nothin' but twinks and chinks!" (Sexy gay young men and
Chinese food!) -JOAT (Jerk-Off All Twinks)
As a quick rule of thumb if I were to actually figure it out it would be 20%
Some jobs require more some less But the 20 % keeps me out of trouble
"Pops" <[email protected]> wrote in message
news:[email protected]...
> I built a spreadsheet that will calculate the board feet needed for new
> projects by putting in each piece and its dimensions. I have built it with
a
> "waste factor" for jointing sites, kerfs, exact widths I need not
available
> when selecting my wood. Since I am a newbie, and don't have enough
> experience yet to know, I was wondering if anyone has a % they use to add
> for waste when you do your own calculations.
>
> Thanks
> Craig Orput
> Cave Creek AZ
>
>
In article <[email protected]>, "Pops" <[email protected]> wrote:
>I built a spreadsheet that will calculate the board feet needed for new
>projects by putting in each piece and its dimensions. I have built it with a
>"waste factor" for jointing sites, kerfs, exact widths I need not available
>when selecting my wood. Since I am a newbie, and don't have enough
>experience yet to know, I was wondering if anyone has a % they use to add
>for waste when you do your own calculations.
>
Depends on the grade of the wood, how much wood I need, and what I'm making.
Grade
=====
Firsts and Seconds (FAS) is supposed to yield 83% clear cuttings, so add 20%
to account for defects. Select and Better (S&B) yields 92%, so add 9%. #1
Common (1COM) yields 67 to 75%, so add 50 to 33%. (Yeah, I know, the numbers
sound weird, but consider an example: you need 10 BF net, you're buying 1COM,
add 50% to get 15 BF. 67% of 15 is 10.)
Amount of wood needed
==================
Suppose you're making one widget, and you need 20 board feet, net, after
cutting out defects and subtracting waste due to odd sizes. You might need to
buy 25 or 30 board feet to get the 20 you need. But if you're making twenty of
the same widget, you can probably get the 400 BF net you require from 450 BF
gross.
What you're making
===============
Cabinet face frames rarely require anything wider than 2" net. 1COM often
yields 90% or better when it's cut into short, narrow strips. Kitchen tables,
OTOH, need long, wide, clear boards. You might have to buy six 8' FAS boards
to get six clear 4' cuttings.
As a general rule, to take into account both defects in the wood and waste due
to odd sizes, I add 20% for S&B, 25 to 30% for FAS, and 50% for 1COM. I
usually wind up with a bit of extra, but that's better than running out.
--
Regards,
Doug Miller (alphageek-at-milmac-dot-com)
In article <[email protected]>, Roy Smith <[email protected]> wrote:
>[email protected] (Doug Miller) wrote:
>> Firsts and Seconds (FAS) is supposed to yield 83% clear cuttings, so add 20%
>> to account for defects. Select and Better (S&B) yields 92%, so add 9%. #1
>> Common (1COM) yields 67 to 75%, so add 50 to 33%. (Yeah, I know, the numbers
>> sound weird
>
>Yes, the numbers sound wierd. It took me a long time to realize that
>these were not just random gibberish percentages, but fractions of
>usable lumber in 12ths.
Exactly.
>
>92% = 11/12
So buy 12/11 as much wood, gross, as you need net: 9% more.
>83% = 10/12
gross = 12/10 net, 20% more
>75% = 9/12
gross = 12/9 net, 33% more
>67% = 8/12
gross = 12/8 net, 50% more
>
>Once you realize that, it's not quite so mysterious.
--
Regards,
Doug Miller (alphageek-at-milmac-dot-com)
[email protected] (Doug Miller) wrote:
> Firsts and Seconds (FAS) is supposed to yield 83% clear cuttings, so add 20%
> to account for defects. Select and Better (S&B) yields 92%, so add 9%. #1
> Common (1COM) yields 67 to 75%, so add 50 to 33%. (Yeah, I know, the numbers
> sound weird
Yes, the numbers sound wierd. It took me a long time to realize that
these were not just random gibberish percentages, but fractions of
usable lumber in 12ths.
92% = 11/12
83% = 10/12
75% = 9/12
67% = 8/12
Once you realize that, it's not quite so mysterious.