SYP Work-bench top movement...

[SARGE..g-47]

Saturday I did my annual flattening of my work-bench top I built in a week-end early last October approximately. The top was not off with the exception of about ..030 rise (about spark plug gap) in basiclly two adjacent pieces of face glued stock 1 3/8" x 3" stock that was acclimated before I did the glue up.

The flattening took about 7 minutes... 10-15 minutes to run a ROS with 100 grit over the entiere surface and tne another 10 to apply a new coat of natural Danish oil. The white or light colored areas show where the top has moved slightly nd the #7 jointer plane flattened. The SYP has pretty much case hardened at this point and is hard as a brick.

So... anyone considering using SYP for a WB top... here is 4 seasons of movement. Summer heat of 85-90 degrees with rain and drought.. 30-45 degrees at night in winter with much humidity in Georgia.

Back to the shop as the oil has cured and Xmas presents are on the agenda.

[jking]

How did you measure the amount the top had moved?

[SARGE..g-47]

How did you measure the amount the top had moved?

All the certified engineers were gone for the week-end so I used the "Southern back-yard shade tree" engineer method which in by no means deems the results scientific but... closer than "eye-ball" but not as close as high tech digital read-outs.

I used trued phenolic winding sticks to locate high spots and penciled them on the top. Then I laid a Starrett 24" machined straight edge across the table from side to side to confirm high spots by looking for light under-neath while the edge was canted so just the tip where the bottom edge and top edge meet touched.

Those gaps where light shone through between the high spots and remainder of the table were measured with a "feeler gauge". The distances varied at different spots but the largest feeler gauge blade I could slide under any spot was .030. Once planed there is no light showing on the follow up test using the machined straight edge.

I would normally not use a feeler gauge but in this case I intentionally did as I decided to do a thread on several forums with whatever results I found. Again... not scientific and conditions will vary with weather conditions in various locals and various shops as there are no two idenical situations IMO.

[pelligrini]

I wonder how's that movement of your pine compared to other common benchtop materials like maple? Still doesn't seem like too much of a variance. Do you think it will lessen of the years?

[SARGE..g-47]

I wonder how's that movement of your pine compared to other common benchtop materials like maple? Still doesn't seem like too much of a variance. Do you think it will lessen of the years?

.030 is no major significance at all really, Pelligrini. If you have a feeler gauge (you can purchase one at any Auto Zone.. etc. for $5 and good to have checking machines) look at the .030 blade and see for yourself. I always flatten a top every year regardless of how much it has moved.. or flatten when I have a piece of stock I am hand planing rock on a side of the bench I am using. That's a tell that flat is no longer flat but you might not notice if you just use the bench for power tools which is not worth bothering with.

As to comparison.. this is around the 24th bench I have built over the last 36 years. Some for sale.. some were gifts and some by commission. The materials have included maple.. beech.. hickory.. oak and last five were SYP. A few I have used and then built another... but from feed-back of those that still have them as most are still local... the movement varies but none including the SYP have been more than 1/16" -3/64" of an inch.

So... I have concluded that the type used is no major concern. Some of the traditional maple have moved both more and less than another as they all have different enviroments they reside in. Again there are no two exact situations they will end up so a comparison would not be a easy task IMO.

Think it will lessen over the years? I simply don't know one way or the other and I believe there is no way to really tell in advance. It's really irrelevant to me as I work in the shop 4-8 hours a day almost every day. If the bench gets out of whack (which they really haven't over the years for whatever reason) I simply flatten it which takes me less than 30 minutes.

Maybe because of careful glue ups and tons of surface that is glued as all I have ever made are 3" thick? Again... I can't really say and simply chalk it up to one of life's mysteries that may never be solved but.. if and when it happens I do have a quick fix that rectifies the occurence in a brief amount of time.

[Hoover]

In your photo of the bench, on the far end you have 2 vises on opposing sides. How do you utilize them? It would appear that for certain glue ups to be an effective clamping device. I see SYP used for benches in several magazine articles. Thanks for the post.

[pelligrini]

.030 is no major significance at all really, Pelligrini. If you have a feeler gauge (you can purchase one at any Auto Zone.. etc. for $5 and good to have checking machines)

Sure do, my plugs get a .035 gap. I think it's about time for another set of 8 too.

That's some good info, thanks.

[SARGE..g-47]

In your photo of the bench, on the far end you have 2 vises on opposing sides. How do you utilize them? It would appear that for certain glue ups to be an effective clamping device. I see SYP used for benches in several magazine articles. Thanks for the post.

I have the twin screw on the end as you see which gets most of the action. I had a front face vise on the left side facing the WB as you see it. I used it for small jobs and sometimes even to hold metal for cutting as I do a lot of jigs and modification to WW machines.

But... I happened to have an extra set of vise hardware someone gave me in a trade and I got tired of walking around the table as most of my work is done from the right side facing. So... now you know as there is no given task they perform together. Could be used for a host of things including glue-ups but... I have a 34" x 44" assembly table behind the WB. And a 48" x 72" assembly talble in my rear shop (1/2 basement) where the wood rack and several mobile machines that are not used as often await roll up to the front cut area.

I just added that recently and if it gets in my way.. I can just un-screw the front face or remove the whole thing in about 5 minutes. But... I sometimes have over 50 clamps in action in phases of glue ups and I have a feeling a purpose will arise in the future.

[SARGE..g-47]

Sure do, my plugs get a .035 gap. I think it's about time for another set of 8 too.

That's some good info, thanks.

You're welcome sir and yeah.. most domestic car plugs get gapped at .035. Now go change those plugs as I need to do on my wife's Cherokee. Well... I'll get to it when my wood stash runs out.

[chopnhack]

I was waiting for a post like this from you Sarge! I knew the SYP would move, at least in my parts, that stuff has some life in. When I get a chance I have to show you a picture of a board I had ripped! Anyway, great thread on the upkeep of your bench and a great reminder of my needing to stock up on some syp for future bench. And a big yes to the hardness of syp that ages, i've bent nails and split the wood on some occasions, if its old, you have to predrill the stuff! Have you heard of heating the wood to solidify the resin? I remember reading somewhere that people have done this to make better use of the wood, as when the resin is still sappy its useless for anything other than construction - a little obscure as it is usually not used for anything other than shop grade or construction.

[jking]

I used trued phenolic winding sticks to locate high spots and penciled them on the top. Then I laid a Starrett 24" machined straight edge across the table from side to side to confirm high spots by looking for light under-neath while the edge was canted so just the tip where the bottom edge and top edge meet touched.

Those gaps where light shone through between the high spots and remainder of the table were measured with a "feeler gauge". The distances varied at different spots but the largest feeler gauge blade I could slide under any spot was .030. Once planed there is no light showing on the follow up test using the machined straight edge.

I thought it was interesting that you gave the measured difference in decimal. I wondered if you used a feeler gauge.

I always appreciate your posts. They are well thought out & informative. I had never thought about using SYP for a benchtop before.

[SARGE..g-47]

I was waiting for a post like this from you Sarge! I knew the SYP would move, at least in my parts, that stuff has some life in. When I get a chance I have to show you a picture of a board I had ripped! Anyway, great thread on the upkeep of your bench and a great reminder of my needing to stock up on some syp for future bench. And a big yes to the hardness of syp that ages, i've bent nails and split the wood on some occasions, if its old, you have to predrill the stuff! Have you heard of heating the wood to solidify the resin? I remember reading somewhere that people have done this to make better use of the wood, as when the resin is still sappy its useless for anything other than construction - a little obscure as it is usually not used for anything other than shop grade or construction.

Are you the one on another forum that had some SYP explode when ripped? It can be nasty under certain conditions.. wet off the shelf builds up resin on a blade quickly... and when ripped it can spread radically or close as you don't know what it is going to do when wet and tension is released.

The guy that had his basically explode said his was dry if I remember correctly. That tells me from using SYP for 36 years that if it was dry the wood was case hardened when he ripped it and you better watch out in that case.

But.. then again I have found other species to do some of the things just mentioned also when wet or containing high energy tension. You just never know until you put a blade to it. And I definitely understand about the pilot holes for nails as my uncle built homes up until the 50's when he passed. I have seen studs taken down that are exactly as you describe after being up and acclimated for years.

But.. I have never heard of the heating you mentioned.. then again as you stated I use it for construction and shop cabinet frames.. etc. etc. But the last 5 benches I have built I have used it and very sucessful in each case. This top cost me under $25 which is not something you can dismiss in a dismal economy when everyone is fighting to keep their economic head above water.

Regards...

[SARGE..g-47]

I thought it was interesting that you gave the measured difference in decimal. I wondered if you used a feeler gauge.

I always appreciate your posts. They are well thought out & informative. I had never thought about using SYP for a benchtop before.

I mainly use decimals when using a micro-meter on machines as increments of inches is the norm in WW. But.. I have never attempted to actually measure the difference as it is not necessary. You just plane until flat normally and the straight-edge and winding stick tell you when to quit.

In this case I did want to derive at something someone could relate to and using the feeler gauge the way I did was the only thing that came to mind. With all the high tech gadgetry being sold to WW anymore.. I wouldn't be surprised if some company came out with a digital reader to measure flatness on work-benches. Now.. that is something every WW needs and must have especially being that it it digital which related to current trends.

Probably the worst thing that has happened to WW I have seen in 36 years is to make digital read-outs available to other than machinist. Someone that gets one.. probably doesn't use it correctly and then claims he has a problem on a 36" rip cut as the ripped line is off .005 over the entire distance. Whoa.... call the manufacturer and demand a new machine that is accurate. It won't matter the manufacturer tells you can't force a nat's behind in a .005 gap even if you strapped plastic explosives on his hinny to try to blast him through. ha.. ha... ha..ha..ha..

As we say down south... "this probably ain't good". With any luck the current trend of attempting to get a WW machine to NASA space capsule tolerances will sub-side and we can get back to WW where we learn wood moves when ripped more than .005 and will compress with glue-up just as much if not more.

As Peter.. Paul and Mary sang... "Where have all the flowers gone" but in this case substitute Wood-workers for flowers.

Have a good day as more woodem Xmas gifts are on the agenda tomorrow. I forgot to post a picture of the top after the quick over-haul I believe so will do so below.

Regards..

[chopnhack]

You got that right about this economy, Sarge. No sir, this is the only forum I have time for! It is an interesting pic none the less. As soon as I get back in the shop, I will take the pic.