Rust is the Enemy

[Susquatch]

Humidity is a constant challenge living here in SW Ontario. Humidity breeds rust like an invasive species.

I saw a thread just now by @Johnwa about this VERY COOL Collet Box he made. I am SOOOOO jealous! Not just because the box is REALLY COOL, but also because I'd be terrified of putting my collects into an enclosed container of any kind in the hot humid climate I have here in SW Ontario.

https://canadianhobbymetalworkers.com/threads/collet-box.3590/unread

I've tried to handle humidity and rust in numerous ways by:

1. Keeping tools and bits well oiled. Spray oil is awesome stuff but can be hard to find. Remington sells a nice spray-on gun oil that is convenient. WD40 sucks cuz it's gone in no time. For long term storage "Fluid Film" seems to work well - it can be had in spray-on form too.

2. Using VOC chips that put rust inhibitor vapours into the air to penetrate micro cracks to stop rust. They can be hard to find. And they dry out too fast. But they work quite well which is why many products are shipped with them. I just wish I could find a bulk supply of the liquid so I could put a drop of the stuff onto the old chips to replenish them.

3. Dessicants to absorb moisture. These work well too but they are a PIA. They go stale way too fast. You can bake them to remove the moisture they absorbed but this is sooooo inconvenient to do. I even bought a special counter top oven to do this, but the wife saw it and confiscated it. Apparently men are not allowed to use kitchen tools in the shop. I did find a Dessicants device that could be plugged in to refresh it, but the cost of getting enough of them was prohibitive.

4. Keeping my shop slightly warmer than outside. With reasonable air exchanges, keeping the shop warm keeps the humidity above the dew point. But rust still happens. On top of that SW Ontario summers are way too hot already. No sane human being would heat a shop that is already too hot.

5. Air Conditioners can be set to dehumidify and cool, but air-conditioning a huge work shop is not really practical. Dedicated dehumidifiers can be too small for a large shop.

6. Keeping things like boxes and drawers slightly open so that humid air cannot get trapped and condense as temperatures go down. I love to keep stuff in drawers and boxes. But that seems to encourage rust. Basically, closed containers trap humid air which can condense as temperatures drop for whatever reason causing rust.

7. Small space heaters and even light bulbs can be used in large cabinets to raise the temperature enough to be above the dew point. This is a great solution but only works in very large containers like cabinets. It isn't practical for most other storage systems.

That pretty much summarizes what I do and don't do and why. But I suspect this group of people have other better ways to deal with rust. I'd love to hear about them! Hopefully others can benefit from the discussion too!

 

[Canadium]

It's an interesting question. I also live in southern Ontario and also have problems with stuff rusting. However my take on the process has been slightly different so far. I always imagined that in my case it was largely a consequence of having an unheated garage. I have an attached poly house which warms it up dramatically on sunny days. So I thought that what was happening is that steel got cold overnight but was slower to warm up during the day than the ambient air. Therefore as the air warmed up again moisture from the air condensed on the cold steel and voila rust begins. I have always assumed that if the temp in my garage was at a more constant level then rusting tools would be much less of a problem. Unfortunately heating the garage would be very expensive. I've tried to reduce the problem by keeping steel stuff covered in plastic. This seems to work to some extent but is very inconvenient when I want to use the tools.

 

[Chicken lights]

I’ve started using gun cabinet desiccant packs in my toolbox. I run a dehumidifier in the shop into a 4” floor drain. On the lesser used tools I’ll spray Fluid Film or similar on them. If I leave the shop door shut it stays 10-15 degrees cooler in there plus the dehumidifier running keeps it way drier. One of the neighbours had his doors open last week and had almost 1/4” of water on his floors, yet mine were bone dry

The gun cabinet desiccant packs I’ve had for a couple years now and haven’t had to dry them once so far

 

[Susquatch]

I’ve started using gun cabinet desiccant packs in my toolbox. I run a dehumidifier in the shop into a 4” floor drain. On the lesser used tools I’ll spray Fluid Film or similar on them. If I leave the shop door shut it stays 10-15 degrees cooler in there plus the dehumidifier running keeps it way drier. One of the neighbours had his doors open last week and had almost 1/4” of water on his floors, yet mine were bone dry

The gun cabinet desiccant packs I’ve had for a couple years now and haven’t had to dry them once so far

If your dessicant packs are still working after a few years, it's obvious that your dehumidifier is working EXTREMELY well! Brand, make, model please!

 

[Tom Kitta]

In Alberta we are a bit drier. The only problem with rust occurred when I had unheated garage. Once it got heated no major issues. I still spray "rust inhibitor" on stuff or just put some light oil if they are not to be used in a while. But heavy or even medium rust does not happen anymore.

In ON I would consider dehumidifier in summer time. With very humid days it is inevitable that at night you get condensation - no one expects the garage (or wants) to be at daily 30C.

 

[Susquatch]

It's an interesting question. I also live in southern Ontario and also have problems with stuff rusting. However my take on the process has been slightly different so far. I always imagined that in my case it was largely a consequence of having an unheated garage. I have an attached poly house which warms it up dramatically on sunny days. So I thought that what was happening is that steel got cold overnight but was slower to warm up during the day than the ambient air. Therefore as the air warmed up again moisture from the air condensed on the cold steel and voila rust begins. I have always assumed that if the temp in my garage was at a more constant level then rusting tools would be much less of a problem. Unfortunately heating the garage would be very expensive. I've tried to reduce the problem by keeping steel stuff covered in plastic. This seems to work to some extent but is very inconvenient when I want to use the tools.

I think you have just been lucky. I have a hard time understanding how covering stuff in plastic really helps unless your conditions are just right. In my mind, a plastic sheet just traps moist air in with the tools where it can more easily precipitate water as it cools down.

It is true that putting cold things into a plastic bag before bringing them inside to warm air stops condensation from forming on the cold metal but that's only because cold air doesn't hold much water and the cold air trapped in the bag gets drier as it warms up.

But the reverse is true when it cools down. In this situation, you want it to be able to breathe.

So I'm at a loss to understand how that works.

 

[Susquatch]

In Alberta we are a bit drier. The only problem with rust occurred when I had unheated garage. Once it got heated no major issues. I still spray "rust inhibitor" on stuff or just put some light oil if they are not to be used in a while. But heavy or even medium rust does not happen anymore.

In ON I would consider dehumidifier in summer time. With very humid days it is inevitable that at night you get condensation - no one expects the garage (or wants) to be at daily 30C.

I'll have to see how big a dehumidifier I can get for my shop.

Not sure that will help with wooden boxes though.

 

[Dabbler]

I lived my first third out in Burlington, which is also quite moist.

FWIW

-- air movement helps, any dehydrator is better than none. and a model maker friend of mine modified his rolling tool cabinets with a 40W bulb in each to raise the internal temperature above the dew point - and ran them 24/7-365.

 

[Susquatch]

I lived my first third out in Burlington, which is also quite moist.

FWIW

-- air movement helps, any dehydrator is better than none. and a model maker friend of mine modified his rolling tool cabinets with a 40W bulb in each to raise the internal temperature above the dew point - and ran them 24/7-365.

I agree with all those points. But I'm not putting a 40w bulb in all my drawers....... Nor in any custom wooden cabinet/box.

Besides the cost, I'd also worry about the bulbs failing. So I might consider a small 5 or 10 watt heater. I don't think it takes 40W to provide great protection.

I did have a small 15w bulb in my safe for that purpose and then I discovered a company that makes a rod heater that is called a golden rod. Something like that might work in my tool drawers if rods for that purpose are available and not too expensive.

At some point, it probably makes more sense to just heat and/or dehumidify the whole shop.

 

[Tom Kitta]

40w bulb 24/7 / 365 is around... 350kw/h per year. That is like... a fridge. I hope he did not have too many cabinets.

 

[Dabbler]

makes a rod heater that is called a golden rod

I've heard of golden rod, but never saw one.

I hope he did not have too many cabinets

He had 2 tall boy metal cabinets for all his tooling...

 

[Canadium]

I think you have just been lucky. I have a hard time understanding how covering stuff in plastic really helps unless your conditions are just right. In my mind, a plastic sheet just traps moist air in with the tools where it can more easily precipitate water as it cools down.

It is true that putting cold things into a plastic bag before bringing them inside to warm air stops condensation from forming on the cold metal but that's only because cold air doesn't hold much water and the cold air trapped in the bag gets drier as it warms up.

But the reverse is true when it cools down. In this situation, you want it to be able to breathe.

So I'm at a loss to understand how that works.

It's really very simple. The obvious case is machined steel tabletops on band saws and table saws. I have actually watched this process happen in my shop. Because the tabletops are shiny flat machined steel it's quite easy to see when a layer of condensation forms on them. Wipe away the condensation with a tissue and seconds later the condensation reforms. So I put a sheet of plastic on the tabletops held down by magnets to block the steels exposure to the ambient air and voila no more rusting tabletops!!!

 

[Susquatch]

I've heard of golden rod, but never saw one.

I did a quick search. Lee Valley sells them.

https://www.leevalley.com/en-ca/sho...T-VGOfJkN2yCPTxJdBRBaGBaw8J8BfsBoCVrEQAvD_BwE

I see they also sell an oil-less rust protector called T9 in both small dropper and spraycan.

I wish I could find that VCI I mentioned earlier in volume liquid to replenish anti-corrosion cards with. That could be kept in boxes and individual

 

[Mcgyver]

as well as oil, what I do....

1) Summertime in the GTA, run dehumidifiers. I have one in the basement shop and one in the garage (house is air conditioned so basement is fairly dry and cool). In the garage it will take buckets of moisture out of the air per week. One good sized dehumidifier, two car garage

2) the rest of the year, the worst damage is done by overnight temp changes - moisture condensing out of the air. Keep things close and covered stops a lot of rust - If you've got 5' of air over top of something, thats a more potential for condensate than if you have 1/2" in a drawer. My experience has been the opposite of yours - keep drawers closed and things in boxes.

3) lastly to minimize condensate keep the shop at the same temp. Unheated shops are imo the biggest contributor to rust. Its big commitment to insulate and heat, but you don't get rust and and the shop is inviting year round.

The TO climate is humid, but doing these things has for all practical extents eliminated rust.

 

[Susquatch]

It's really very simple. The obvious case is machined steel tabletops on band saws and table saws. I have actually watched this process happen in my shop. Because the tabletops are shiny flat machined steel it's quite easy to see when a layer of condensation forms on them. Wipe away the condensation with a tissue and seconds later the condensation reforms. So I put a sheet of plastic on the tabletops held down by magnets to block the steels exposure to the ambient air and voila no more rusting tabletops!!!

I don't question what you observed. But I really don't think it's simple at all. I'd like to understand how and why that works. The need to understand things is a cross I bear 24/7.

The physical process is not intuitive to me. I suspect that it's a volume thing that could actually be worse than it looks. Perhaps your steel is rusting overnight whether or not you use the plastic despite the appearance of condensation.

Re-reading your earlier post,

I have an attached poly house which warms it up dramatically on sunny days. So I thought that what was happening is that steel got cold overnight but was slower to warm up during the day than the ambient air. Therefore as the air warmed up again moisture from the air condensed on the cold steel and voila rust begins. I have always assumed that if the temp in my garage was at a more constant level then rusting tools would be much less of a problem.

I assume the "it" means garage is what is warmed up by the attached sun room.

But here is my problem with that. I assume from what you say that everything gets uniformly cold overnight, and that no moisture condenses on the steel surfaces during that cool down (which is hard to believe on its own). Then, as the air warms rapidly, the steel doesn't warm and acts as a localized condenser due to the temperature difference.

But my understanding of the process doesn't work that way. Yes, cold steel brought into a warm MOIST air environment will condense water onto its surface. However, air that was not humid enough to condense water at a low temperature will not condense water at higher temperatures than it was under the overnight condition no matter what the temperature difference is. In other words, it isn't the temperature difference that matters. It's whether or not the dew point is reached. Since the air wasn't condensing water at the stable overnight condition, it shouldn't be able to condense water as its temperature increases because the relative humidity is crashing. Even the air next to the steel cant get any colder than the overnight temp so it shouldn't condense either.

Unless I am missing something, I suspect that the humidity in the air in your garage is increasing (which is not normal at all) for some other reason as the air warms up. Perhaps sunlight is causing convection in the air from a high humidity source? Perhaps opening doors allows an inrush of warm moist air from elsewhere?

 

[Johnwa]

We’ve definitely got a different climate in Calgary. We usually have humidifiers to add moisture to the air. My wife has one on her piano to keep the sound board from drying out. There’s also one of those golden rod thingies underneath but I doubt it ever comes on.
I will put some desiccant packs in the box though just in case. @Susquatch thanks for the heads up.
John

 

[Susquatch]

as well as oil, what I do....

1) Summertime in the GTA, run dehumidifiers. I have one in the basement shop and one in the garage (house is air conditioned so basement is fairly dry and cool). In the garage it will take buckets of moisture out of the air per week. One good sized dehumidifier, two car garage

2) the rest of the year, the worst damage is done by overnight temp changes - moisture condensing out of the air. Keep things close and covered stops a lot of rust - If you've got 5' of air over top of something, thats a more potential for condensate than if you have 1/2" in a drawer. My experience has been the opposite of yours - keep drawers closed and things in boxes.

3) lastly to minimize condensate keep the shop at the same temp. Unheated shops are imo the biggest contributor to rust. Its big commitment to insulate and heat, but you don't get rust and and the shop is inviting year round.

The TO climate is humid, but doing these things has for all practical extents eliminated rust.

I think your experience and advice is very helpful.

Personally, I find drawers and boxes to be the kiss of death. In fact, that's what prompted this thread. I saw the box that @Johnwa made and drooled with envy. I had just opened a box with HSS tool bits in it that looked like it had been bathed in saltwater. The box was right next to other tools that were in the open air and just fine.

My guess is that the 1" of air that gets trapped in your boxes with your tools was dry because the box was closed while your dehumidifier was operating.

I agree that heated shops are wonderful. So are air-conditioned shops. But my machine shop is 40x80 with 20ft ceiling. I have tractors and other farm equipment in there and I feel blessed to be able to have some room for other fabricating and repair equipment. It is insulated and heated with overhead gas radiant heating, but not air conditioned. I keep it just above freezing in the winter because I need running water in there. Winter is never a problem for me. There is enough winter air leaking in and out that when warmed up by the heaters, is dry as a bone. Summer is my bad time because the shop floor is like a big cooler that cools the humid summer air which then condenses. Of course, that's also when big huge doors get opened to move tractors and other equipment in and out.

We do have a big basement in the house too. It has also been a problem because we try not to use the air conditioner unless we have to. I generally restrict the airflow through the fan in order to slow it down through the air conditioner evaporator. That really drops the air temperature through the coils and improves the dehumidification. But since we don't use the a/c very much, we end up with high humidity. We solve that with two huge dehumidifiers. The result is a nice dry basement ever since we started doing that. In fact, I can't keep up with emptying the pails so I run a drain tube into the gravel under the cement floor and I let the sump pump look after it.

My take on what I have heard from others here so far is that I need to buy a half dozen big dehumidifiers for my shop. Perhaps I could set them up with staged settings that get rotated so they don't all run at the same time.

 

[Chicken lights]

If your dessicant packs are still working after a few years, it's obvious that your dehumidifier is working EXTREMELY well! Brand, make, model please!

I haven’t forgotten- I should be home tomorrow or Saturday

 

[Dabbler]

@Susquatch - @RobinHood has a solution in his 40X80 shop: He partitioned off a section, and put a roof over it (primarily to use a s mezzanine storage... Thatsmaller volume can be heated/cooled/dehumidified at lower cost, and leave the tractors out in the big part that is moist...

 

[Susquatch]

We’ve definitely got a different climate in Calgary. We usually have humidifiers to add moisture to the air. My wife has one on her piano to keep the sound board from drying out. There’s also one of those golden rod thingies underneath but I doubt it ever comes on.
I will put some desiccant packs in the box though just in case. @Susquatch thanks for the heads up.
John

I was born in rural Saskatchewan over between Humbolt and Viscount. I hear you. Those people don't have a clue what the word humid means! But they sure as heck understand dry.....

Still very jealous of your box...... It's gorgeous.