New pump front cover - how bad is this scratch?

[Ignoramus]

Drain plug seat cracked on front cover of Pentair Challenger High Pressure, so I got new part.
New part has a gouge on o-ring interface. Old part has similar markings but not so big.

How bad is this? And if bad, how do I fix it: just fine grit sand paper or sand paper followed by acetone?

in my past life I've dealt with high vacuum systems, and o-ring interfaces had to be impeccable. So this gouge provokes deepest loathing.

 

[Newdude]

Assuming (*Usual disclaimer applies) that you can't return it, or can't afford the downtime it will take, then you have nothing to lose by trying. I'd lightly sand it flat again and attempt to do about the same on the good half. As long as it's flat and reasonably plumb, (the two halves being ll and not \l ) the O-ring should bridge the gap. Also, pool lube is amazing stuff and has performed some pretty big miracles at times so with any luck you'll be good to go between the two.

It sucks you have to doctor a $150 part.

 

[Newdude]

It not like you're working on one of J Beezos's 165 pools and he's being a cheapskate. You're rubbing 2 pennies together trying to help your kids school. Karma kinda owes you a solid here IMO.

 

[Ignoramus]

Assuming (*Usual disclaimer applies) that you can't return it, or can't afford the downtime it will take,

Yes, exchange would have been lengthy and the pool had already sat without circulation for 4 days . I decided to turn off the pump: there was a small but solid stream of water gushing from somewhere around drain plug. It was mesmerizing

I ended up sanding down entire surface as evenly as I could, and, per your advise, slathered silicone lube on the o-ring. No leak after 1 hr, and I'll check tomorrow how it holds up after a standard 4 hrs.

It sucks you have to doctor a $150 part.

Yep. Ain't it ironic: I was afraid of shoddy parts and went for Pentair OEM part. Now, I wonder if custom molded product would have been a fair gamble.

Thank you @Newdude !