Wood Board Thickness - erratic

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ezurick

Wood Board Thickness - erratic

Post by ezurick »

I mentioned in another thread that I purchased a 13" Wen Planer so I can plane the cheap boards I get from Lowes (box stores) such as the white pine that is kinda cheap (8x8x8 is around $11). Well, I am still having issues with board thickness when it comes to doing very small accuracy cuts or carves. Some areas of the board barely get carved, while others dig in. I use a Digital Vernier Caliper to measure thickness and found the cheap board such as the pine from Lowes has variable thickness. And I don't mean from one board to the next. I mean I measure the thickness on one side and it is random. .728 to maybe .758. YES! that much. I flip the board over and ALWAYS the measurement is different. Same board! So this explains why it is uneven although my waste board i level from milling the whole top.

So I decided that I'll pay a little more for their so-called quality or premium boards in a different aisle. Yellow Pine, Oak or Poplar are the common ones in my Lowes. Took measurements on both sides... again, same thing. So ALL boards are out of whack for thickness accuracy.

When I am etching small letters with a .003 depth.. those width differences can ruin the carve. I haven't found ONE board that has the same measurement on each side, nor from one area to the next. I figured the so-called premium boards should be more accurate than what they are.

So I decided that since most of my projects are small, I will use a 3/4" or 1" end mill and shave off around .002 to try and get a better level before each job. What a hassle and what a mess those bigger end mills create. Not all my projects need the precision of thickness. It is mainly on carving I am doing that are small and need accuracy. What do you guys do to handle these erratic thickness of box store boards? If you plane the board... it will come out the same as it was but smaller... both sides and areas sometimes have a .0010 difference or more, which can be critical when etching something. Am I the only one struggling with this?

Sorry to ramble... but I wanted to make sure I tried to explain this as best I can.

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Re: Wood Board Thickness - erratic

Post by gkas »

ezurick wrote:So I decided that since most of my projects are small, I will use a 3/4" or 1" end mill and shave off around .002 to try and get a better level before each job. What a hassle and what a mess those bigger end mills create. Not all my projects need the precision of thickness. It is mainly on carving I am doing that are small and need accuracy. What do you guys do to handle these erratic thickness of box store boards? If you plane the board... it will come out the same as it was but smaller... both sides and areas sometimes have a .0010 difference or more, which can be critical when etching something. Am I the only one struggling with this?
No, this is a common problem. I routinely use a 1.25" planing bit to surface my stock before critical jobs. Sometimes I lay out the board so that I plane all except corner clamping pads. I do this by drawing an oversize rectangle, and excluding four corner patches from the planing. That keeps me from running over clamps. An alternate method is to stick the board down with a couple of strips of double-sided tape or blue tape with super glue (preferred). I may even run the planing step as part of my job steps. I almost always run all but the cutout steps from 'Material Surface', but then recalc the cutout steps and run those from the 'Machine Bed'.

Finally, my best method to date is purchasing a drum sander. Boy, does it sand flat. It sands flat, cleans up box edges, and generally makes life a lot easier. But you better have a good dust collector. I still use the tape method for small pieces and where I want to take off quite a bit of material.

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Re: Wood Board Thickness - erratic

Post by Bob Reda »

Don't know what machine you got, but shopbot is accurate to .01 of inch. If .001 inch is messing you up you are in wrong profession. That is 1/10 of a hundredth of an inch??? I've been doing woodworking for many a year and if my project ended up .01 I would be tickled to death. Wood expands and contracts. You are correct that a planer will not even both sides, that's why most times for many woodworkers they mill one side flat on a jointer. But .001 of an inch. I don't believe any machine or man in the world can get that with wood. Metal on the other hand, maybe. What I do for the situation you mentioned is make a file for the particular area you are having a problem with and run that part, even if is a letter in a word and work it till you get the look you are after.

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Re: Wood Board Thickness - erratic

Post by martin54 »

Couple of things, firstly as has been said wood moves, I had real problems when I first started working with wood because I couldn't seem to do anything very accurately, 20 years as a mechanical engineer in the RN I was trained to turn/mill to a very high standard & got very frustrated because I thought I had lost those skills :lol: :lol:
The wen planner you bought looks to be a thicknesser from a google search, I am in the uk so not familiar with them, a thicknesser on its own is not enough to get a good flat board. You need one good side to start with or all you do as you have noticed is make the board thinner :lol: :lol:
as Bob says you need a jointer to get one side flat, difference between the 2 is that a planer has its infeed & outfeed tables at the same height & a jointer does not. Often machines are advertised as planer thicknessers incorrectly, they are actually jointer thicknessers so pays to have a propper look if in the market to buy one.
When you levelled your spoilboard did you also check the spindle was trammed properly ? This can also make a difference when carving small detailed work. :lol:

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Re: Wood Board Thickness - erratic

Post by alan254 »

When I need a project to be really true i just put it on the cnc and surface it just like you do the spoiler board on the cnc machine. This will bring it true to your router eliminating and deficiencies in the wood or the machine.

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Re: Wood Board Thickness - erratic

Post by Phil »

Your planer may need adjustment. If you plane a wide board is there a difference in thickness one one side of the board versus the other side?

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Re: Wood Board Thickness - erratic

Post by wb9tpg »

I do use a Delta Planer but sometime plane it on my CNC using a 1" Whiteside bit. On those jobs I find it useful to ZERO to the TABLE.
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ezurick

Re: Wood Board Thickness - erratic

Post by ezurick »

Thanks for the replies and feedback folks. I feel a little better knowing I am not alone with this. Of course I realize that .01 isn't that much for normal carving. But I've found these cheap boards from box stores (Lowes in my case) are a lot more than that within the different areas of the same board. I didn't record the differences and honestly don't remember exact measurements... but it was alarming to find those same differences in the so-called premium boards. Yes, the planer doesn't do any good to correct that and on precise carves, I will mill the top with a large end mill first.

Lastly, I am rather new to a lot this. My experience history is related to being a machinist in my past, long ago; but a cubicle junkie since the early 90's. And yes, that was all precision metal. Never wood. So I know how to read various measurement tools. But I have to say that when engraving something like small letters with a 20 degree V bit at .003 depth, a board that has a reading of .728 on one side and .750 on the other makes a big deal. And I have found some with those differences. So yes, mill the surface first to fix this. I was wondering if there was something easier and a lot messy... a jointer sounds good until I started looking at prices. :( I can afford one that does small width cuts. But the machines to do something like an 8" width board is out of my financial league. This may sound elementary, but I know what a joiter does, just don't have one to experiment. If I get a 6" jointer, will that be able to successfully plane a 12" board by flipping it? Meaning joint one side and turning it around and doing the other side. Will it be level?

thanks again.

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Re: Wood Board Thickness - erratic

Post by martin54 »

If I get a 6" jointer, will that be able to successfully plane a 12" board by flipping it? Meaning joint one side and turning it around and doing the other side. Will it be level?


I am a novice when it comes to woodworking but I would say no to the above question, any twist, bow cupping or what ever in a piece of wood is not going to be uniform so i just can't see that working very well, I am in the same sort of position, would love a machine capable of dealing with wide boards but even decent used machines over about 8" re out of my price range. Did consider buying one spares or repair but then I am just making work for myself that I really don't have the time for :lol: :lol:

If you are getting differences in thickness across the board might be worth checking that the cutting head is sitting parallel to the feed table on your thicknesser, don't trust the factory settings on a lot of these machines at the cheaper end of the market, I have a thicknesser that I believe is the same sort of benchtop machine from a google search, out the box it was off by quite a bit, thought about taking it back but figured that the next one could be just as bad so just spent the time to adjust it myself :lol: :lol:

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Re: Wood Board Thickness - erratic

Post by Phil »

If you buy cheap materials you will often get poor results. Old saying "garbage in garbage out." That being said even expensive wood can have issues due to movement; natural stresses, moisture content etc. For that reason many woodworkers but rough wood from a sawmill. 4/4 (1") thick wood can be milled to an accurate thickness with well tuned equipment. The various problems such as warping, cupping etc. can be dealt with to get a flat, accurate 3/4" board.

Phil

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Re: Wood Board Thickness - erratic

Post by SteveNelson46 »

I have a DeWalt 13.5" planer. It's not industrial grade but it works good for a hobbyist. When I buy wood for a project, I look for rough cut (plane sawn) lumber so there is a little extra thickness to work with. If that isn't available then I buy the next thickness that is available then plane it to the dimensions I need with a final pass or two on the drum sander. When I need a board flattened that is too wide for my jointer I use a sled that firmly holds the board as it passed through the planer. Once one side is flat it's easy to flatten the other side.
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Re: Wood Board Thickness - erratic

Post by mtylerfl »

Hi Steve,

What brand/model drum sander are you using?
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Re: Wood Board Thickness - erratic

Post by SteveNelson46 »

mtylerfl wrote:Hi Steve,

What brand/model drum sander are you using?
It's a Performax 16-32. I'm not sure if they even make them any more. Jet bought them out a few years ago but all of the parts are interchangeable. The sandpaper rolls are a little pricey. Especially if one tries to use it as a thickness planer.
Last edited by SteveNelson46 on Fri Jan 25, 2019 5:36 pm, edited 1 time in total.
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Re: Wood Board Thickness - erratic

Post by mtylerfl »

Thank you!
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Re: Wood Board Thickness - erratic

Post by Bob Reda »

Yes you can joint a 12" wide board with a 6" jointer by flipping it around. You are only putting arm pressure on the wood, not like a planer where the infeed and outfeed rollers are set to a high pressure that can straighten out the wood only to have it go to original twist when it passes the outfeed rollers. Woodworkers do this all the time.

Bob

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