Mower deck sheet metal thickness

[mmmmmdonuts 274]

I have a 1991 520h 48" mower deck and there are a few holes in it that are fairly big. I wanted to know what gauge sheet metal is usually used to fix these decks. I think I have 20 or 22 gauge on hand but I didn't know if that's too thin. 

[953 nut 55,081]

I think they are all 18 gauge.

[mmmmmdonuts 274]

Thank you for the information. 

[Tankman 3,518]

16 gauge, or better use 14 gauge.

I unbolt stuff in the way, bolt up with patch.

Remove after stitch welding the patch.

Prime and paint. SS hardware and Never-Seez.

[Stormin 9,981]

 The main reason mowing decks rust and get holes, is that users do not clean them after use. Wet, damp grass left on will soon allow rusting to take place, especially over here in the UK. I always remove and clean my deck after use. Bit of a bind I know, but only costs a bit of time.  Better and cheaper than trying to source a decent used/new deck. For winter storage, I coat the underneath with old engine oil.

[mmmmmdonuts 274]

That's what I do with my other deck and plan on doing with this one. I take them off at the end of the year and thoroughly clean them and paint the underside every year before spraying with an oily substance typically with fluid film. This deck that I am patching is part of the 520H that was given to me, so I am trying to clean it up as best as I can. Honestly knowing the deck has nearly 2200 hours on it and most of the paint is in great shape other than those few holes is surprising to me a bit. I will try and get pictures of it up here of the actual damage. When I got the deck unfortunately there was so much wet grass everywhere I didn't know there were 3 huge holes.