Fighting Summer Humidity on WW Tools

[moparfreak]

This summer so far has seen a lot of humidity where I'm at (midwest). I took the family on a vacation for a week and just came back and find my cast iron tools (Tablesaw, Jointer) are showing surface rust. My hand planes are also showing. I've used Carbon Method on the tablesaw cast iron surfaces but it seems it wears off after a few projects. This is disappointing. I know I probably just have to re-apply stuff more often, and especially in the warmer months, but anyone have any tried and true tricks?



For the hand planes I think I'll need to apply a wax or some sort. I'm also thinking of getting a bunch of desiccant bags to keep in the those cabinets.

Adam

 

[Shiftless]

I use carnuba furniture wax on my vintage Craftsman cast iron table saw. I don’t know how much wax wears off onto projects but I don’t make jewelry boxes or anything critical.

 

[neophyte]

Renaissance Wax.
It’s a microcrystalline mineral wax developed for protecting antiques at museums.
You buff a small amount into the surface, and then buff the excess off quickly.
It is also excellent for smoothing surfaces, and removing friction. I’ve used it on router plunge rods to make the plunge routers plunge much smoother.
You do have to make sure you buff excess wax off quickly though, since the wax dries hard.

 

[RTM]

Try VCIs (ie Bullfrog) for your planes, if you keep them in a chest or cupboard.

Only thing that works for me living near the ocean.

For cast iron tools in use, Johnson’s Paste Wax has been my go to. No residue to worry about removing, a quick swipe with mineral spirits will take most off, unlike oil based stuff.

 

[Rockable]

How about a dehumidifier? I have one in my shop and nothing rusts. As you know, it also gets humid here in the South.

 

[moparfreak]

For my handplanes I had a VCI emitter (Zerust brand I think) but it was quite out of date (2020, ugh). So, that's on me. I've refreshed it to two new ones and will look into the Bull Frog brand as well.

I think on the large cast iron worksurfaces, I'll just need to make it a habit to reapply coatings a lot more often (like every month or so). Wish I could just spray everything down in a light film of oil, but that doesn't work well for wood working projects, unfortunately....

Adam

 

[mike93lx]

How big is the shop? I've always kept a dehumidifier in my garage and it keeps rust under control

 

[American Locomotive]

The reality is any coating outside of a super hard durable paint (and even that will wear eventually) will rub off basically as soon as you start using the tool. You will then need to reapply it when you're done. We've tried them all, basically. Any rust-preventer sprayed on a surface that sees handling/abrasion will wear off quickly.

Desiccant bags are a waste of time unless your cabinets are extremely air tight. They'll just be constantly absorbing moisture and get used up very fast otherwise.

My tools live in unconditioned space. I found that laying old rags "damp" with wd40/oil on top of my cast iron machinery when not in use seems to keep the rust away. They're not dripping wet, so they don't seem to leave a residue on the cast iron surface. But I'm also not doing fine woodworking either.

A dehumidifier in a shop, in an area that gets hot & humid in the summer, is generally a poor idea in my opinion. They use just as much (if not more) power than a window air conditioner AND they make the space significantly hotter. You'd be better served by an air conditioner. That way you can have a cooled AND dehumidified space. Dehumidifiers can make sense if it's a basement shop or the spring/fall, but for summer - an A/C is a much more practical solution.

If you do not want to condition the space, my recommendation is to just integrate applying your rust preventer into your post-project clean up routine. You probably clean off the saw anyways when you're done with a project. Just add another 45 seconds to spray and wipe down the machine with your rust preventer.

 

[moparfreak]

The reality is any coating outside of a super hard durable paint (and even that will wear eventually) will rub off basically as soon as you start using the tool. You will then need to reapply it when you're done. We've tried them all, basically. Any rust-preventer sprayed on a surface that sees handling/abrasion will wear off quickly.

Desiccant bags are a waste of time unless your cabinets are extremely air tight. They'll just be constantly absorbing moisture and get used up very fast otherwise.

My tools live in unconditioned space. I found that laying old rags "damp" with wd40/oil on top of my cast iron machinery when not in use seems to keep the rust away. They're not dripping wet, so they don't seem to leave a residue on the cast iron surface. But I'm also not doing fine woodworking either.

A dehumidifier in a shop, in an area that gets hot & humid in the summer, is generally a poor idea in my opinion. They use just as much (if not more) power than a window air conditioner AND they make the space significantly hotter. You'd be better served by an air conditioner. That way you can have a cooled AND dehumidified space. Dehumidifiers can make sense if it's a basement shop or the spring/fall, but for summer - an A/C is a much more practical solution.

If you do not want to condition the space, my recommendation is to just integrate applying your rust preventer into your post-project clean up routine. You probably clean off the saw anyways when you're done with a project. Just add another 45 seconds to spray and wipe down the machine with your rust preventer.

I think you're right. The shop is sealed and insulated and attached to the house. I have a hanging shop furnace and a window AC but I do not run them all the time, just when needed to remove the chill or heat for working. Otherwise I'd have a ridiculous energy bill. I'm not a fan of running a dehumidifier as it's just gonna be an energy **** and another thing taking up valuable floor space in the shop.

I'll just have to work maintenance into the protection habit of the cast iron a lot more. I have things like Carbon Coat, T9 Boeshield, etc, just need to have them handy at arm's reach to reapply after using.

I guess I'm just sad that my nice sawstop looks like $&%# after coming back and now I need to scotchbrite it!

Adam

 

[Dagny]

I leave dehumidifier set on 45% and have central air but i'm in the business. Only need ac here about 1 week a year.

 

[u3b3rg33k]

I have a dehumidifier in my detached, insulated garage, and I have it controlled not by its own settings, but set on constant with a thermostat-controlled outlet. it runs WAY less, and is set for 50% (turns on at 51%, off at 49%), vs on/off constantly seemingly without reason like it does when left to its own devices.

zero rust on any of my tools in years, and it's more comfortable when it's not 55%+ humidity out there.

if your garage is well air-sealed, it won't consume much energy, since air leaks are likely the big source of humidity gain.

 

[loganb]

Minisplit solved the same issue for me. Downside on humid but cooler days like today is I don't want to open the doors(attached garage) but it's a small price to pay for year round comfort. The electrical bill difference was negligible on before/after it was installed.

 

[308guru]

Bostik Topcote (maybe called Glidecote now?) spray is awesome in preventing rust and also makes work surfaces as slick as can be.

For longer storage, and to be removed prior to use, try LPS3.

 

[moparfreak]

This spray is awesome in preventing rust and also makes work surfaces as slick as can be.

For longer storage, and to be removed prior to use, try LPS3.

Which spray are you referring to?

Adam

 

[zendriver]

Unless I was using it often, I'd wipe the saw table down with oil and be done with it. Otherwise wipe with WD 40

 

[LeeG]

I use Boeshield T9 on all my cast iron surfaces. Works great.

Lee

 

[Nutria]

You might get better mileage from Johnson's Paste Wax than the spray-on treatments. It takes longer to apply of course, as well as more elbow grease. And paste wax won't last forever either, but worth a try.

 

[jar944]

You might get better mileage from Johnson's Paste Wax than the spray-on treatments. It takes longer to apply of course, as well as more elbow grease. And paste wax won't last forever either, but worth a try.

It's been discontinued for a while now.

 

[RTM]

It's been discontinued for a while now.

I bought 4 tins at an estate sale $4, two lifetimes supplies. Gave one each to two friends, suspect I'm good for a while

 

[Nutria]

It's been discontinued for a while now.

I bought 4 tins at an estate sale $4, two lifetimes supplies. Gave one each to two friends, suspect I'm good for a while

Yep, me too, I have four tins, also courtesy of estate sales. I don't even pick them up anymore. I think that lots of us have cans squirreled away.

 

[jar944]

Yep, me too, I have four tins, also courtesy of estate sales. I don't even pick them up anymore. I think that lots of us have cans squirreled away.

I switched to varathane. Smells better and is readily available. 1 can lasts a couple years.

 

[pcmeiners]

"The electrical bill difference was negligible on before/after it was installed." minisplit

A minisplit kept at a reasonably low temperature, in a standardly insulated shop, will keep a shop at an even temperature so you will not get rust. If you want to fight rust another way you will need to coat every metal surface... that is every drill bit, die,tap, saw table, motor shaft, every small tool. On the other hand a minisplit kept at a reasonable temperature ( not super cold) costs extremely little to run. Have a 1080sqft garage, cost around $8-10 /month on average, with a temperature higher than needed for condensation control.

 

[308guru]

Which spray are you referring to?

Adam

I updated my post with the missing info.

 

[Renegade1LI]

After I polish the CI I apply a clear coat of urethane to all the surfaces, works great & no wax transfer. I also keep the ac on all season so that helps alot, here on LI its 85% humidity. The nice part of using a clear coat is just touch up as it wears.

 

[jar944]

I did nothing except insulate the garage doors with polyiso. However since my shop is attached to the house it stays above freezing and below 90 without me doing anything.

Keeping the doors shut as much as possible is enough to keep rust/condensation from happening.