I always give a quick cleaning with a wooden stick after each mowing. Works for me. However, if I were to spray anything on the underside, it would be this. http://www.corrosionx.com
It has a remarkable tenacity.
I use a similar lanolin compound to rustproof my cars. It stays tacky. I can only imagine that everything would stick to this coating. Is this something new to the mowing guys or do they have a lot of years experience with this stuff?
It's a big thing in snowblower circles, but I don't think it would work too well with grass and dirt. We have an electric mower now with a plastic deck, but our old gas ones never really got treated with anything. All the rust that might form seemed to get sandblasted off with regular use. I might apply a coat of WD-40 (Fluid Film seems too sticky and long-lasting) during storage to inhibit corrosion, but treating it during on-season use doesn't seem necessary to me.
You could treat this mower as an experiment and do an application of spray-on bedliner or other heavy duty coating. My main concern would be whether it would create too much friction and places for blades of grass to grab onto.
I agree that no coating of anything will last on the underdeck. The abrasion of the grass, twigs, stones, etc., will wear it off. Just clean off the grass with a stick. I've never had an underdeck rust out. Other parts of the lawnmover will be shot long before that.
When I was a kid my parents used to buy Murray mowers and the decks would rust off long before the motor ever died. They would clean off the grass after every mow. That said I bought a Murray when I got married 14 years ago, I paid like a $100 for it, I seldom cleaned the deck and I still got the mower and it is solid as a brick. I bought a Lawnboy, 5 years ago, because Iam a 2 stroke nut, and wanted to get a new one before they quit making them, I clean it out about every third cut and it has no rust. My conclusion is, that they use alot better steel now or better treated, I should say. When is the last time you saw a car seriously rust out like you used to see in the 70s, its rare. If it makes you feel good, Id give it a shot of WD40, after you clean out the grass every week, but I feel you have nothing to worry about. They dont rust out like they used to.
The one before this one did, I bought it at a Estate sale for like $15,I sold it to a freind before leasving PA and he's still using it. The one I bought was in 1998, steel deck, last of the two strokes. Not nearly as wicked as that aluminum deck one, that thing would cut down a tree if you could get on top of it.
My parents bought 19" 2-stroke Lawnboy in 1980, it was still mowing the lawn at their cottage last summer. They replaced the pull cord mechanism twice & the muffler once before the sold the cottage in 2000. Had my boat moored at a old neighbour of theirs last summer, buddy that bought the cottage from them used that old lawnboy every weekend we were up, still going strong.
I have a 2-stroke Lawnboy that has served me for 16 years. I bought it used, so I'm not sure how old it really is.
I almost threw it out once when I had problems with it. It turned out to be nasty carbon buildup in the exhaust that needed to be cleaned out.
My thoughts on this old thread:
On a mower, generally the controls break, the muffler rusts and the steel deck rusts in places. The engine itself is often the most durable part.
Some surface rust underneath is seldom an issue but look out for rust at weldings, gaps, joints. Those parts rust even if you remove clippings.
I would stop cleaning clippings so much and just make sure that all joints, welds and plate gaps on the mower is protected by some anti corrosion oil. I would also store the mower in a dry shed. That way the clippings won't cause anything other than surface corrosion unless you cut the seaside golf course.