Sanitizing Pruning Tools

I hope I didn't seem confrontative about temps on pruning. I just don't know and I was casting about to see if there were any published protocols. I read that in an autoclave a temp of 270F will sterilize unwrapped steel tools in 3 minutes. I don't have anyway of knowing, but it seems like there ought to be a sweet spot with a temperature high enough to sterilize quickly, but low enough to preserve the temper in the blade. This is making my brain itch, so I'm going to look around to see what I can find, and post any findings here.
 
OK I didn't quit ............ I lied.

Autoclaves are pressure vessels which sterilize with Temp, time, and very high pressure.
Unwrapped steel tools would have been washed cleaned of all debris before the autoclave !
It still took 3 min. That's 3 min per side if treating a blade w/ flame.
No pressure; Lots of debris, resin, pitch, sap; No control of flame temp; ......

Good luck on your search ! :-)
 
GregManning said:
OK I didn't quit ............ I lied.

Autoclaves are pressure vessels which sterilize with Temp, time, and very high pressure.
Unwrapped steel tools would have been washed cleaned of all debris before the autoclave !
It still took 3 min. That's 3 min per side if treating a blade w/ flame.
No pressure; Lots of debris, resin, pitch, sap; No control of flame temp; ......

Good luck on your search ! :)
Click to expand...
I think I have a paper or literature review at home regarding eradicative pruning. I'll dig around when I can.
 
Thanks Greg! There's a big difference in temperature though between the 270 f attained in an autoclave under pressure, and the 3,623 °F at the business end of a propane torch. I guess I'm trying to find the minimum temperature that would instantly kill pathogens, and from there establish how long an ambient temperature saw blade would need to be exposed to the torch flame to reach that temperature.

.........still digging.
 
In 1984 I spent 10 months working in Fermoy, Ireland on the Black River.
(I know that's not the UK, but I was in the neighborhood ;-) )

Some of us are still trying to figure out how to do things across the pond !
 
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Ok, here's what I found thus far. The way the process is described in the published study I found, they're recommending keeping the end of the torch appx 1 inch away from the blade and moving it back and forth over the length of the blade. Doing this for 10 seconds killed 95% of pathogens, while doing it for 40 seconds killed 100%. http://horttech.ashspublications.org/content/19/4/695/T7.expansion.html

My take-away is that if you swept the torch from the base of the saw to the tip and back over the course of one second, repeated it 19 times and flipped the blade over to do the same on the other side, you'd be able to achieve total sterilization, and likely do so without heating any single part of the blade to the point that it turns blue with the temper drawn.

Excerpted from the article:

"Because leaf removal in palms is rarely limited to only brown leaves, it is prudent to sterilize saws between trees when working with palms susceptible to pruning-tool-borne diseases. We found that using a portable torch to flame the saw blade was an effective and rapid method of saw sterilization. We suggest brushing debris from the saw teeth before flaming and to flame until any remaining debris turns to ash, a process that takes only a few seconds."

Here's how they described doing it:

"TOOL SANITATION. We verified the presence of the canary island date
palm wilt pathogen in canary island date palm at Irvine by isolation and microscopic identification. Petioles from these palms were cut with a pole saw blade (9s; Fanno Saw Works, Chino, CA) to load the gullets of the saw blade with infested palm tissue. Flame from a propane torch (Type Z; Ace Hardware, Oak Brook, IL) was held 1 inch from the infested blade and moved along the blade for 0, 10, 20, or 40 s. "
 
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That does sound like the best option, however, it will ruin the temper set on the saw teeth. Those points are tiny and will heat up fast.

Still, there are plenty of fast cutting and inexpensive handsaws.
 
Guys I think this is a fascinating discussion. This horttech citation/ study had good rigor (small P value) but I'd like to know if the fungi in question are sporulating fungi - i.e. were they killing just mycelia or spores as well. Spores can be a bear to deal with (as in the barbicide citation above). Any chance to maybe ask the author(s)?
 
Here's another way to skin the same cat. I do a good bit of root pruning with reciprocating saws and pruning blades. I found this Milwaukee folding jab saw that mounts reciprocating blades of any type and will close like a pocketknife with a 6" blade. I had to have it!

https://www.milwaukeetool.com/hand-tools/saws-and-cutters/48-22-0305

These are the cheapest pruning blades I've found for reciprocating saws, so naturally they're the ones I use.

http://www.harborfreight.com/9-in-4-5-tpi-reciprocating-saw-pruning-blades-5-pc-68946.html

I love them. I can root prune all day on one blade, down and dirty. These will be too long to close up the blade into the handle, but you can buy 10 of them for less than a $20. Half of them up in the tree with the arborist, being switched out, while the other 5 are being sterilized by a groundsman with a pair of pliers and a torch. Just crazy enough to work!
 
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ghostice said:
Guys I think this is a fascinating discussion. This horttech citation/ study had good rigor (small P value) but I'd like to know if the fungi in question are sporulating fungi - i.e. were they killing just mycelia or spores as well. Spores can be a bear to deal with (as in the barbicide citation above). Any chance to maybe ask the author(s)?
Click to expand...
As long as you're the one tracking down the authors and questioning them, there's a chance. ;-)
 
I will try follow up with authors to see what can be found then.
In meantime, a safety minute story about torches. If you're using a small hand -held propane torch with the burner nozzle and valve screwed onto the little propane tank that's one thing. But there are flexible hose models of various sizes out there with a burner nozzle/ igniter/ valve connected by flexible hose to a gas valve built onto a screw on fitting with another valve on the top of the propane tank. Years ago I was involved with a fatal burn incident where a plant operator had been heating a line with a tiger torch, turned the gas flow off at the nozzle but not at the tank and put the hot torch down. The torch rolled onto the hose, melting it in a spot which then allowed a gas release. The resulting gas cloud ignited from static discharge from non-rated equipment in the area and two guys were badly burned, one with lung involvement to which he succumbed two days later in ICU. I wanted to pass this along as perhaps a safety moment for orchard pruners, etc. to watch out for, depending if you're using a torch with flex hose and if you are getting into larger propane tank sizes with more potential for generating a gas cloud. I never want to see anyone go through the same thing again. So if this situation fits please take moment to talk to your guys and perhaps relay this story.
Hence my own preference for chemical sterilization (in chemical process plants here, torch use is often a safe work permit controlled task).
On another note, I am wondering, if you have power nearby, if a paint stripper heat gun thingy couldn't be used rather than flame. I have one that is darn near thermonuclear in heat output. Might be easier on the saw teeth than flame? (Is there Commercial Opportunity for tinkerers to set up an electric saw sterilizer rig and/or for a saw manufacturer to make a saw handle that can cope with high temperatures without melting or deforming) Just a thought.
And still wondering about sealing the pruning cuts in case of fungus as above.
 
OK, this ought to to get me blacklisted (again) ....................

Just as a point of information:
The ISA ITCC Rule books have always stated - Section 2.2.2:

"It is the responsibility of each competitor, judge, technician, and/or volunteer to ensure that all equipment meets Rule 2.2.1 and is fully functional, clean, and contaminant-free. This includes ensuring that all volunteers’ cutting tools have been disinfected before starting work on the ITCC trees."

I have volunteered for 67 TCC's over the last 10 years. (including 4 ITCC's, 1 NAmTCC, etc)

2016 Ohio TCC, was the first organization, in my experience, to set up a "disinfection station" that ALL setup climbers went through, before cutting anything !

Nice Work Ohio ! ! !
 
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As per citations above in this thread, should the above rule actually read "sterilization" rather than "disinfection"? (Although a big bold sign that said "Sterilzation Station" might give some folks great pause - :-)
Tom/ anyone that's been around for a time - I've been wondering why there's no section(s) in ANSI Z or in TCIA Best practices (that'I've seen) on a scientifically validated tree tool sterilization procedure - formal.
Might this all make a good Masters thesis for someone looking at bacteria/ viruses/ fungi and spores?
 
ghostice said:
Tom/ anyone that's been around for a time - I've been wondering why there's no section(s) in ANSI Z or in TCIA Best practices (that'I've seen) on a scientifically validated tree tool sterilization procedure - formal.
Might this all make a good Masters thesis for someone looking at bacteria/ viruses/ fungi and spores?
Click to expand...
I don't just like this idea, I LOVE it ! ! !

A Disinfection Research Project / or "Master's thesis for someone looking at bacteria/ viruses/ fungi and spores?"
 
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