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View Full Version : Table saw vs. pressure treated lumber



jay gill
06-13-2010, 12:23 AM
I know there are some less than friendly chemicals used in pressure treated lumber, but never expected the top of my table saw to rust in little over 2 hours from the cutoffs I left on it.

I attached the pictures I took. I was amazed. I keep the top of the table covered with Boshield. I guess it wasn't enough.

Joe Chritz
06-13-2010, 12:25 AM
Been there, done that.

The copper in the new treatment is horrible on metals.

If you catch it early it cleans up well.

Joe

Darius Ferlas
06-13-2010, 12:29 AM
The funny thing (or perhaps not so funny after all) is that the exact same thing happened to me and I have exactly the same TS. You were lucky to have noticed the rust within a couple of hours. My PT lumber was sitting there for two days. I managed to remove the rust but some discoloration (darker sport) still remains. The wax did not protect the cast iron from that. Nothing to worry about though as far as the TS's performance is concerned.

Paul Atkins
06-13-2010, 12:57 AM
Where did all the sawdust go?

jay gill
06-13-2010, 9:01 AM
Saw is hooked up to the Ridgid shop vac and when I'm done with a particular set of cuts, I vacuum up around the saw for anything that isn't collected.

This particular setup, with the original blade and metal insert, (kept it around exactly for cutting pressure treated or dirty rough lumber, as to not use my Woodworker II or Freud rip blade) does collect less sawdust than when using the zero clearance insert.

I think more to your point though is that, yes, I am now really,really afraid of ever inhaling any of the sawdust from cutting PT lumber.

Lee Koepke
06-13-2010, 9:06 AM
I just bought an inexpensive blade set (28 tooth rip and 60 tooth crosscut ) from the Big Blue Box Store for $35 ... for this kind of application.

Thanks for the reminder though, hopefully I dont forget to move my cutoffs.

joe milana
06-13-2010, 9:12 AM
Same thing happened to me once working with some "green" 4 x 4 cedar posts from the BORG. I left the off-cuts laying on the tablesaw and bandsaw and the next day when I cleaned up, rust under every piece. I think alot had to do with the moisture content of the wood, and I should have known better. The rust cleaned right up, but the stains remain as a reminder.

Praki Prakash
06-13-2010, 1:23 PM
I cut some pressure-treated 4x4 (just four cuts) on my table saw. A week later, I was greeted with rust all over it. I don't quite know if it is the treatment or the high moisture content - it was literally dripping as I cut it.

How is one expected to work with green PT lumber? Stick to a circ saw or aluminum table tops?

Myk Rian
06-13-2010, 1:45 PM
Been there, done that, got the T shirt.
I used Bar Keepers Friend to clean it up.

Ray McCullie
06-13-2010, 1:55 PM
You need to let PT cure for a few weeks before you work it. It's normally green when you get it. Or so I've read.

Cody Colston
06-13-2010, 3:04 PM
I think the high moisture content of PT lumber is the culprit more than the chemicals. I've had the same thing happen just from setting a green bowl blank on my TS for a couple of hours.

You did good vacuuming up the sawdust asap because it will also rust the top since it's wringing wet, too. When cutting wet lumber, even without leaving a piece on the TS top, it's a good idea to wipe the cast iron down with mineral spirits after vacuuming off the sawdust and then re-applying whatever you use for rust preventative.

Jim Rimmer
06-13-2010, 5:07 PM
I have seen and read enough here on the Creek that I am obsessive about leaving anything laying on a table top. And I don't know what I would do if I had to cut PT lumber. I guess take it outside and use a circ saw.

Howard Acheson
06-13-2010, 9:43 PM
It happens all the time. When I first go into woodworking at a shop with a number of experienced folks, the first thing I was told was to never leave any wood or anything else on a cast iron surface.

Pressure treated wood is a major offender.

Curt Harms
06-14-2010, 8:50 AM
It happens all the time. When I first go into woodworking at a shop with a number of experienced folks, the first thing I was told was to never leave any wood or anything else on a cast iron surface.

Pressure treated wood is a major offender.

Of course there's lots of iron under the granite top. Granite top and good dust collection?