Magnesium Mites?

[Hermio]

I would suggest it may have been stored/abandoned on a crushed rock limestone floor or near a battery storage area. The plastic wasn't affected but some how an acid splattered/wicked up to the magnesium. as far as water and ph level concepts I understand that from some boiler experience.. But when fresh mortar or concrete gets wet it is the lime/lye that supercharges the acidity of your wicked up water. I am not a chemist but have done masonry enough to acknowledge seeing mortar salting from a wall. Apply that to a few of my saws and knowing their history gives me this notion.

Lime is basic, not acidic. It will not increase acidity. But both alkali and acid attack magnesium. (I am a Chemical Engineer).

 

[FamilyTradition]

All, I know creosote can be damaging to iron and steel. What about magnesium? Example: say one was using a saw to cut railroad ties or the like and then failed to clean the saw afterwards? Just throwing a thought out there. Max.

 

[rogue60]

 

[KASH]

If creosote is toxic to iron and steel why did every rail road use creosoted ties with the steel tie plates spiked flat onto the creosoted tie?
Kash

 

[KASH]

in Oct 2000 I was out in my boat checking beaver traps up a river west of my house,I got 3 beaver and stopped and cut a boat load of birch with my Stihl S10.I was heading home at slow speed and it was a beautiful fall day about 60 degrees I just turned into my bay when the nose of the boat started going under I had been picking up water in the front end I could not see.Well the logs were floating every where and I saw my saw sink to the bottom.I grabbed the boat rope and swam the 100 yards to shore it was very refreshing so to speak.I pulled the engine off and dumped the boat best I could and paddled home
I made drag hooks and tried several times over the next three years to retrieve the saw. but I finally got the saw with a 12x12 magnet on a rope.
Heres what I found bar and chain were rust pitted but salvageble the motor was good after clean up and carb job but on the s10 and 08 saws the oil tank has the handle bar attached to it and the oil tank has the steel bar studs going threw it with nuts to secure the bar and chain. The oil tank was completely eaten away in a circle around the bar studs and the oil tank became two pieces instead of one. I use this piece when I teach my solar classes so I can show them why you do not mix different metals around electric current.
I always had a dream that one day I would pull the one day old brand new 1959 Evinrude the Lesage boys lost overboard in 59 but now I dont think there would be much left of it.Galvanic action in high mineral concentrated fresh water lake.
Kash

 

[calamari]

I always had a dream that one day I would pull the one day old brand new 1959 Evinrude the Lesage boys lost overboard in 59 but now I dont think there would be much left of it.Galvanic action in high mineral concentrated fresh water lake.
Kash

Great story and a great lesson.
I have a 22' aluminum center console boat that I used in both fresh and salt water. I was fastidious in rinsing it and the trailer off after being in the salt right after launch and retrieval. We have very soft water here that is snow water in most of the lakes that has passed over a lot of limestone so I diidn't rinse it off after being in the lakes. None of my other or any friends aluminum boats have trouble with corrosion in our lakes.
The boat and galvanized trailer have that gray aluminum and galvanizing oxidized color but no signs of any corrosion that you can often find in aluminum boats used in the salt...except...right in the middle of the transom. The boat is very sea worthy and as a result they made it with a high flat transom that is maybe 3' of uncluttered metal high. Right in the middle of that field of metal I noticed a perfect circle of what looked like sand blasted metal about 10" in diameter. When I looked closer I found it was actually a crater with a pin hole in the .080" aluminum. Clearly some electrolysis had taken place because there was no place for any salt to have adhered there.
I had two batteries in the boat on separate circuits so I could at least have one charged battery to start the motor to get home on. All electronics were grounded to the negative sides of the batteries with buss bars but I didn't ground the boat to anything. I guess i should have but couldn't think how w/o inducing a current flow.
It doesn't take a long time for aluminum or magnesium sitting on or in a caustic solution to begin to be eaten up by electrolysis. If Kash had only put a zinc on his saw before he threw it away. The Lesage boys motor probaly had one on their motor but as acid as some of those tannic lakes are it wouldn't have helped for long.

 

[Canyon Angler]

A friend of mine has an aluminum jon boat he uses for ducking in saltwater, and he used a piece of modern pressure-treated wood in it (I think to put the battery box on) and got holes in the aluminum under the PT wood. Apparently they changed the chemicals used in PT wood, banning arsenic compounds and using copper compounds instead, and the copper next to the aluminum with saltwater in-between = bad juju.

You've got to be really careful with copper around aluminum in boats. A tiny piece of copper wire left in the bilge will eat right through aluminum like alien blood. They say that if you use Kopper-Kote gasket cement in an outboard motor where it's in contact with saltwater, it'll eat up the aluminum faster than you can spit.

 

[calamari]

A friend of mine has an aluminum jon boat he uses for ducking in saltwater, and he used a piece of modern pressure-treated wood in it (I think to put the battery box on) and got holes in the aluminum under the PT wood. Apparently they changed the chemicals used in PT wood, banning arsenic compounds and using copper compounds instead, and the copper next to the aluminum with saltwater in-between = bad juju.

You've got to be really careful with copper around aluminum in boats. A tiny piece of copper wire left in the bilge will eat right through aluminum like alien blood. They say that if you use Kopper-Kote gasket cement in an outboard motor where it's in contact with saltwater, it'll eat up the aluminum faster than you can spit.

Makes sense. Good tip.

 

[KASH]

Canyon Angler thanks for the copper tip I should have known this being an electrician and making sure no copper touches the aluminium cable trays when we do ground bonding.Here is the sad part I have a beat up 12 foot Reynolds Wrap aluminium boat sold from Sears a real light weight boat nice to portage but a beaver knocked a tree on it .The boat was upside down and the bottom was caved in at the front.I straightened it out but the sides would vibrate when trolling so I ran 3/4 copper tubing around the outside and attached the aluminium to the copper.Now that you have refreshed my mind I will have to tear it apart in the spring it sure worked good also put a rubber pad on the transom.
Calamari I never threw the saw away it is a good running 08s now.The lesage motor and others from that era did not have the zinc annode as the boats were mostly wooden The zinc showed up on OmC in the seventies.
Kash

 

[calamari]

Calamari I never threw the saw away it is a good running 08s now.

By "throwing it away" I meant into the lake. It's an old family expression meaning everything from losing your wallet to getting a divorce.

 

[Bob Hedgecutter]

Despite having owned alloy pontoon boats, having retrieved outboard motors from the seabed (not my own), having to replace copper hot water cylinders every five or so years (on a good run, sometimes every 2-3 years) and having bolted on the odd zinc anode before today- I believe I may have found a cure for the magnesium mites in that 61.

 

[dirtcurt]

Lime is basic, not acidic. It will not increase acidity. But both alkali and acid attack magnesium. (I am a Chemical Engineer).

I left a gun case on the concrete floor and over time it got white powder from the concrete on the case. I figured out what was going on and cleaned the case by hosing it out. I let it dry out completely and stored a AR-15 in it a few months later. Fortunately, I decided to go shooting and took it out of the case maybe two-three weeks later and couldn't believe my eyes! It was rusting at all the metal areas and even the black aluminum receiver had 1/8" little white powder zits randomly through the upper and lower. I was able to save it with CorrosionX and it made it back to service with the corrosion stopped and never getting worse. It was an original Colt too!

 

[dirtcurt]

Even though you say that saw has never cut any palm trees it has cut something that has a similar chemical in it that caused it to eat away at the magnesium. Maybe some kind of bush or other plant that you have there.
I have seen this before and it was always from Palm trees here in the US.
I have a Jonsered 670 that looks just like that.

In California that's practically the first thing I check when looking at a saw. If the saw has been in landscaping, you may as well forget about it. If it's been in landscaping AND they are selling it, there is a problem, even if the saw looks good.