Kohler head resurfacing help/update

[LAWN BOY]

Hello again. Before I get started I just want to say how thankful I am for the help I have received on this forum.
I have made a little progress on resurfacing the cylinder head off of my IH Cub Cadet 70 since my last post. However I noticed low spots around the edges and did my best to circle/outline them in the below picture. I didn’t notice them until now.
Also, in a previous post it was recommended that I use 150-180 grit sandpaper instead, but is that even worth it considering how far I am?

https://www.onlycubcadets.net/forum/...pictureid=8280

[Cub Cadet 123]

I cannot open your picture for some reason, but see if this helps. Oh, I would use 220 grit sandpaper and just be patient. Tape a full sheet on a pane of glass that is horizontally placed on a hard surface. Slowly do figure 8's on the sandpaper with the head without applying pressure to it. The weight of it will gradually plane your head off. Slow and steady wins the race!!!

Cub Cadet 123

[BKsCC]

Alternative to a glass pane: I had success going to a local granite countertop retailer and asking for a scrap piece of granite, ended up with a 2in thick 18x18in chunk. That's dead flat too and it sure as hell ain't gonna move around on your bench wherever you plonk it down, and you don't have to worry about it shattering on you.

[LAWN BOY]

Originally Posted by Cub Cadet 123

I cannot open your picture for some reason, but see if this helps. Oh, I would use 220 grit sandpaper and just be patient. Tape a full sheet on a pane of glass that is horizontally placed on a hard surface. Slowly do figure 8's on the sandpaper with the head without applying pressure to it. The weight of it will gradually plane your head off. Slow and steady wins the race!!!

Cub Cadet 123

I should’ve mentioned that I am about 65 percent done and that I’m using 320 grit wet/dry sandpaper. I’m wondering if it would be worth going down to something coarser like 220 or even 150-180 at 65 percent complete…?

[West Valley G]

I wouldn't hesitate to go to your 220. Get it most of the way done and
then switch back to your finer grit. Nothing worth working on comes
without the effort. Your getting there. You won't have to think about it
again once your finish up. I always like that part about doing it right once.

Ken

[OverKnight]

Regarding what grit to use to flatten your cylinder head, an analogy is sharpening a chisel or a knife. You could use a 600 grit stone to do this, but it would take longer than forever. Start with a coarser grit, such as 180 - 220 to quickly remove most of the material and then finish with a finer grit for the final finish. 320 would probably be good for the final sanding; I don't think I've ever used anything finer than 400 on an aluminum cylinder head.

[Ambush]

I'm not sure about aluminum heads like on the Kohler, but for cast iron you definitely don't want the surface too smooth. A bit of "roughness" grips the gasket better. I use a milling machine and leave a cross hatch, but if using just sandpaper, I don't think I'd go l finer than 220. You want flat more than smooth.

[ol'George]

Some of the newer Vehicles with aluminum heads specify a rougher surface just as you mention, or the gasket will leak.

[OverKnight]

Ambush and ol' George, I agree with both of you.

[LAWN BOY]

I think I’ll order some 220 grit wet/dry sandpaper to finish it. I might try to reinstall it before it’s all the way done like Ambush and Ol’ George mentioned and hope it doesn’t blow again. I can’t wait to have this thing running(hopefully) in the spring!