How much increase in bdft of material beyond what the project calcs to?

[George Bokros]

How much extra do you buy for waste, ooop's and sawdust, 10%, 20% more less??

I do not have room to store much more excess stock.

Thanks

[Mike Henderson]

That's really difficult to answer because it depends on a lot of things. When I go to buy wood, I try to figure out how I will located the pieces I need on the wood I'm buying. Sometimes things don't lay out nicely and you have to buy a fair amount more than the board feet you calculated. Sometimes the wood is a lot wider than you need and the pieces you rip off can't be used on the project.

Other times, things work out exactly right.

Also, it depends on the mistakes you make and that's hard to calculate.

But as a rough guide I'd say 20%. The problem with buying too little is that when you go back, you can't find wood that really matches what you bought originally.

Mike

[Matt Day]

Higher the better. Depending on the size of the project and cost of wood i’ll Go as high as 50%. Better to over buy than take the time to go back for more.

[Larry Edgerton]

I figure estimates at 25%, always rough stock but then usually buy 50% more if I am low on that species. If the wood is inherently difficult I will bump it up accordingly.

[Cary Falk]

I shoot for 20%. Sometimes it is too much. Sometimes it is not enough.

[George Bokros]

That's really difficult to answer because it depends on a lot of things. When I go to buy wood, I try to figure out how I will located the pieces I need on the wood I'm buying. Sometimes things don't lay out nicely and you have to buy a fair amount more than the board feet you calculated. Sometimes the wood is a lot wider than you need and the pieces you rip off can't be used on the project.

Other times, things work out exactly right.

Also, it depends on the mistakes you make and that's hard to calculate.

But as a rough guide I'd say 20%. The problem with buying too little is that when you go back, you can't find wood that really matches what you bought originally.

Mike

I try to do this also but sometimes I loose my place in my laying out because i figure some this part and some of that part in single piece then try to figure out what you have already accounted for after doing this with several pieces.

[glenn bradley]

The eternal answer . . . it depends. Like Mike, I have a list of parts when I go looking through my stacks or through the yard. I check off the parts as I find them and even chalk them out on the boards before I ever get to the register. I may want a specific sort of figure for drawer fronts. This pattern may or may not be near the edge of a board, follow the mills rip lines and so forth. This means the blank for that drawer front may come out of an odd position in the board and at an angle. This results in more spoil but, I get the look I am after. Odd pieces of spoil can be used for small parts, secondary wood on another project or even a whole project if it is small enough. I can say without reservation that I would rather have 10bf left over than have to go back to the yard and try to find a matching 3bf for a project 90% done ;-)

[roger wiegand]

it really depends on the quality of the wood and the details of what you are trying to cut. I've lucked out and only used 5% over the total, other times 50% barely made it. I'd guess 20% is a reasonable average, but you really don't want to get caught one board short. If you are cutting a lot of small pieces you don't need to be over by as much-- Always cut your large pieces first. It also depends on how carefully you match grain and color and pay attention to which board goes where. The fussier you are the more extra you will need.

For very expensive wood or special figure I will plan cuts very carefully, perhaps changing the dimensions of the project to fit the board.

90% of what I do is made from cherry, maple, and walnut with poplar as a secondary wood, so I just keep a good stock of those on hand so I don't run out in the middle of something, or make a bad compromise "making do" with what I have on hand.

[Rod Sheridan]

Hi George, if you're accounting for sawdust, then start with 25% as that much normally winds up being removed by jointing and planning.

Another 10% for end trimming, maybe 10% for stock selection and another 10% for trimming.

That works out to 55% which seems about right looking at my records for various furniture pieces, however I've been at 100% or more when I really wanted nice grain matching...........Rod.

[Ted Derryberry]

If you're buying 4/4 and milling it to 3/4" you need 25% for the milling alone. However, who figures a project like that? I figure how many lineal feet of a certain width and thickness I'll need and go from there. I take my list and a calculator to the lumber yard and see what's available. Sometimes I want 10' material but have to buy 12'. That can be a 20% loss right there or I can sit down and refigure how to cut my parts out of 12s instead of 10s and reduce the waste. I'll usually buy 5% over on the quantity of boards just to allow for screw ups on my part. If I don't screw up I save it for the next job. Consider that I'm hand picking each board so there's usually no real surprises unless I completely miss something.

One variable that I didn't see mentioned above is the project itself. If there are a lot of "back sides" and other hidden areas where you can use up less than perfect material then your waste factor goes way down. Larger projects also tend to have less waste as there will be more total parts, including small parts which can eat up the offcuts and "bad" boards that you can't get a long piece out of.

[Lee Schierer]

I buy my lumber S4S from my supplier. I have a program I purchased years ago that allows me to enter lengths and widths of pieces. I can select the size of the raw material I want to use to make that part. The program will optimize the way to cut the pieces from lengths of stock. For initial calculations I use standard lengths (i.E. 6, 8', 10' etc.) and the program calculates the best way to cut the pieces and how many pieces are needed for each width of board. It allows for kerfs as well. Once I purchase the material, I measure the actual length of each board I bring home and enter those lengths as "stock" material. I can also include lengths of material left over from previous porjects and un the optimization again. This usually results in a significant amount of left over material from what I purchased. If I make no mistakes when cutting i normally have enough wood to make the project. Errors or design changes sometimes cause extra material to be purchased.

The program is called Sheet Layout (http://sheet-layout.software.informer.com/download/), but it is no longer being sold. There are some trial versions that can be downloaded, but those versions have limits on the number of pieces you can enter. The licensed versions had larger part capabilities.

[Don Bullock]

Other than figuring out the cost of a particular board I don’t even consider board foot in creating projects. My projects are always based on the grain pattern in the wood. I try to maximize the visual affect and perhaps strength of the wood I’m using for each part of the projects I make. While this process may create more waste and therefore increase the cost I believe it is worth it.

[Brad Shipton]

It also depends if you get to pick it yourself or not. My stock comes on a truck and is picked in a warehouse by a picker. If you get to pick it, then 25% as Rod suggests can be fine, but in my case it can be more. If working with Cherry or Walnut it also goes up a lot more if you need to cut off the sapwood.

[Bill Adamsen]

I buy different hardwoods and from a variety of suppliers, typically local sawmills though some stocking resellers. It comes in many flavors from d4s to rough. I find few woods source consistently enough to provide a blanket statement. Roger's statement is pretty much my story. Occasionally project specific requirements such as one of the oaks. 25% is probably the best number for estimates.

[Brian Holcombe]

For projects I cut all the time, 10%. For new projects 25%.

[Jim Becker]

Lately, I've been under-shooting way too much, so in many cases, I'm moving more toward 30-50% extra, depending on the species. I'm also pretty anal about matching grain and color as someone already referenced, so that always requires a little more, even when choosing my own material carefully at the vendor.

[John C Cox]

A huge amount depends on the work you are doing.
Is it a show piece or a utility piece?
Is it going to be painted or finished with something clear?
Will the piece have fabric covering?
Are you trying for a very uniform look or a look with a lot of character which can make use of "defects" in the wood as part of the design?
Does the size of the piece maximize lumber or will it leave you a ton of incidental cutoffs?
Are you picking the lumber or are they?

For example - with my acoustic guitars.... Lumber I hand pick often ends up 60-75% waste... And that's after I pick the 1 board out of the huge stack....

But - the small shelf I made for the living room wall was maybe 10% (after me picking the wood) because I cut everything out of 1 board that I picked for the purpose.. The only waste was whatever was left on the end of the board.

[Rich Engelhardt]

George,
I try to shoot for 50% - - but - -I usually end up using that or a little less.
The biggest problem is I get to conservative at the beginning and trim things way too close to the exact dimensions I need.
Then as I go along, I'll notice I have a pretty good pile of wood left - - so I relax a little and get more picky about the grain and such.

Then when I get all done - -I have a good sized pile of - - both unworked wood and cutoffs that are too small for anything and too big to burn :D :D & the pile that's left isn't big enough to make anything else with!!!

:D :D

[Simon MacGowen]

How much extra do you buy for waste, ooop's and sawdust, 10%, 20% more less??

I do not have room to store much more excess stock.

Thanks

Factors like your machine set-up (how ready and quick you can produce extra stock to the same spec.) and proximity to your lumber yard matter. Your woodworking skills also count: Are you prone to making mistakes or are you good at fixing mistakes without starting over with fresh stock?

If I am planning to use the same kind of wood for my next project, I will allow more for wastage, etc., say 50% or even more because the extra stock is not scrap afterwards. But for one-time projects, I won't go anything more than 10%. Sometimes, using existing rough lumber in my storage, I may just have enough for a project without any allowance for waste.

Woodworking magazine articles tend to suggest a higher % of waste because they cater for less experienced fellows.

Simon

[Charles Lent]

For much of what I do it usually falls in the 20-25% range, but many factors can bump this in either direction. I've been under estimating quite often lately, so I'm being a little more careful about making sure that I don't buy the last of what they have, so I can go back and get "a few boards more" when I need them so they will better match what I've already bought and used.

Charley

[John C Cox]

They also suggest a higher % of waste because they can't really control what you buy... And you have to buy whole boards to get the wood you want... And trees aren't really all that good about pre-planning their growth around the sort of cuts I need for a project.. ;)

I honestly believe that most of us run far higher waste % off boards than we think we do... Why? Because we simply don't keep any records of what we bought vs what we used and the fully usable stock that was left.. And often we save all sorts of junk cutoffs that eventually find their way into the fire....

Just as an exercise - I did the calculation just now on the last guitar back and sides sets I resawed out of lumber. 79% waste from the boards.... I would have guessed around 50%...

[Art Mann]

The answer depends, in part, on the quality of the wood. My sawyer has a pile of reject cherry, maple, QSWO and sometimes other species that he sells for $1 bd-ft. It isn't suitable for furniture but I buy it all the time to make boxes and CNC router made gift items. I probably discard 50%+ but it is still worth it at that price. I mostly uses pieces that are 16 inches or less long. Sometimes, this wood contains some spectacular grain.

[Keith Hankins]

30%, but i quit buying for individual projects. I just buy lumber and put it aside when a deal comes along. Buy in bulk if you can.

[Mike Henderson]

30%, but i quit buying for individual projects. I just buy lumber and put it aside when a deal comes along. Buy in bulk if you can.

Ah, if only I had the storage room:)

Mike