Mold and grass buildup on mower deck underside

[ultrarunner]

Mowing dry buildup never a problem.

I have motors outlasted steel decks.

My best combo is aluminum deck but then I replace worn out wheels every 15 to 20 years.

No experience with composite deck.

 

[Too many Kubotas]

Loss of lift from blades.

Hmm. So when the crud builds up on the sides, to me that's a bit like a better fitting fan shroud on a radiator.

But you're saying it leads to less lift. How come? (I've obviously never spent time thinking about this, or much about mowers in general).

 

[mike carter]

I have a John Deere D140 with a bagger that I use for the first few mows of the season to prevent all the dandelion seed distribution. I know it's not ideal to mow wet grass, but sometimes that isn't an option, and the grass has to get done (even though it means stopping every few laps and unclogging the chute to the bags).

I went out to the garage yesterday after mowing the lawn and could smell the wet grass under the mower deck. I took it off and spent the next two hours with a putty knife and wire brush scraping the grass off. It varied in depth from almost a thin wax like coating, to about three inches in some spots.

I have scraped most of it off I do believe, but would like to do something to it to prevent this from becoming an every time I mow thing. And yes, I will attempt to get the lawn mowed late afternoon, early evening when it is at its driest, but again, not always an option, and I will be ordering some new high lift blades to hopefully help with moving the cut grass across the deck and up the shoot.

Not sure if I will have to remove the blades and then pulleys to do a proper sanding, priming and painting/treating, or if there is some magic trick I can just apply now?

Thanks in advance folks.

I spray my 60 in deck on my kabota and also 48 in fabricated deck on Cub cadet with fluid film quite generously and when I take off in the fall I have almost no mold or grass on it at all before I started doing that I was scraping stuff off all the time so it works great for me , I know people will say waste of time but I assure you it works extremely well

 

[brbhan]

I have a John Deere D140 with a bagger that I use for the first few mows of the season to prevent all the dandelion seed distribution. I know it's not ideal to mow wet grass, but sometimes that isn't an option, and the grass has to get done (even though it means stopping every few laps and unclogging the chute to the bags).

I went out to the garage yesterday after mowing the lawn and could smell the wet grass under the mower deck. I took it off and spent the next two hours with a putty knife and wire brush scraping the grass off. It varied in depth from almost a thin wax like coating, to about three inches in some spots.

I have scraped most of it off I do believe, but would like to do something to it to prevent this from becoming an every time I mow thing. And yes, I will attempt to get the lawn mowed late afternoon, early evening when it is at its driest, but again, not always an option, and I will be ordering some new high lift blades to hopefully help with moving the cut grass across the deck and up the shoot.

Not sure if I will have to remove the blades and then pulleys to do a proper sanding, priming and painting/treating, or if there is some magic trick I can just apply now?

Thanks in advance folks.

Shortest distance between two points is a straight line. Simplicity.
Following each mowing session I merely take a garden hose fitted with a variable spray nozzle and shoot water at high pressure at deck underside. Means bending a few minutes to hit all surfaces from both sides of tractor model GR2110. Because I cannot see the surfaces I visualize from memory the underside configuration. Freshly cut grass falls off in clumps.

Kubota decks are magnesium, I believe. So, rust is not an issue or observed in past ten years of ownership. Blade spindles are mounted on cup-like hubs to hold lots of grease that, I assume, is fed as hub gets warmer during run. Water will not displace grease in enclosed grease cup; water-RESISTANT, not water-PROOF.

Come time to switch-over to snow-blowing (Northeast), deck scraping is minimal.

 

[Mcdust]

Unfortunately, nothing is close to permanent. There are products such as MoDeck for that purpose. I've seen those who wax the underside of a new deck to the guy who used bedliner. I've personally tried grease paint on a brand new and prepped deck. The dirt fines picked up by the blades are an effective sand blaster. I have customers who park on a mower lift and scrape it each time.

How about a few coats of an epoxy paint such as POR-15? Glossy (slippery) and hard as nails.

 

[Runner]

But you're saying it leads to less lift. How come? (I've obviously never spent time thinking about this, or much about mowers in general).

I'll take a stab at it and say, IMHO, it is because to get the lift you need a certain quantity of air to move in a specific direction. Built-up grass reduces the volume available and messes with the path of airflow. Also creates friction in the airflow, slowing things down. Just my layman's guess...

I spray my 60 in deck on my kabota and also 48 in fabricated deck on Cub cadet with fluid film quite generously and when I take off in the fall I have almost no mold or grass on it at all before I started doing that I was scraping stuff off all the time so it works great for me , I know people will say waste of time but I assure you it works extremely well

I will have to say that the 54" deck on my CC ZTXS5 54 does stay remarkably clean. I only notice build-up in a couple of areas: a little bit right around the holes where the spindles enter the deck, a little at the rear corner of the discharge chute and one other corner inside the deck (I think it is a corner behind the middle blade. Otherwise, bare steel in there.

 

[5030]

Kubota does not and never will make a deck from magnesum or magnesum alloy. Way to expensive to even consider doing. They are for the most part, fabricated steel. No manufacturer would ever build a deck from magnesum alloy in as much as it cannot be fabricated, it has to be pressure die cast. Far as water contimantion of the spindle bearings when power washing the underside of ANY deck, they will all suffer from that water contaimation of the bearings. Why you shoud regrease them after doing that deed and for those that have sealed spindles (no grease fittings) it only hastens the spindle bearings demise.

Much better to manually clean off the cud versus using pressureized water to clean it.

Don't say I didn't warn you...lol

 

[saxtonhill]

I drive my scut up onto car ramps after each use and use a garden hose to spray off grass which I then put in my compost.

 

[Too many Kubotas]

I'll take a stab at it and say, IMHO, it is because to get the lift you need a certain quantity of air to move in a specific direction. Built-up grass reduces the volume available and messes with the path of airflow. Also creates friction in the airflow, slowing things down. Just my layman's guess...

Sticking with my radiator shroud comparison, the volume would be coming from below the blades just like from the front of a vehicle's radiator.

And to maximize the effectiveness of the fan, the shroud should fit a tightly as possible relative to the fan.

Of course, then the air then has to go somewhere, and on my "single prop" 6-footer it exits left, judging by where the cut grass ends up.

 

[6string]

I just finished scraping all the moldy crap out from under the deck on my S240 and sharpening the blades. I blew the mower off with electric blower and the storage compartment door on the right fender flew open revealing a nice sized red wasp nest. I switch the blower to high and never saw them or their nest again and they didn’t show up later. We have had rain after rain after rain the last two months and the ground is saturated. I serviced my zero turn yesterday and it had mow muffins caked up under it badly too. It’s 81,sunny and humid now. I think I’ll mow some later this afternoon. The ground is too soft to use the small tractor and finishing mower.