I was given a Varsity the other day. I was thinking of making it a a gravel grinder / backup commuter. I am not putting much money into it (tear down, gease, new cables, tape and going with the kenda k161 cross tires).

I think that I want to get rid of the chain guard and the large ring and make it a 1x5. My question is will I need to leave the FD on to act as chain guide?

The frame has a lot of chips but doesn't really have rust (it does have the expected rust on some of the chrome). The person who gave it to me purchased it from a yard sale 3+ years ago. I don't think he ever did anything to it. The bike itself appears to have been ridden in the past and has had a series of replacement parts: Weinmann levers, dia compe center pull brakes, the front wheel is alloy the stem does not appear to be original. The chain, tires and brake pad look relatively new.

Buy a BMX chainwheel.

That's one option, but might not be necessary.

I have a 1x8 setup on my commuting bike. I don't use a FD or a chainguide. I've dropped my chain twice in the last year as a result, but it's really easy to put a chain back on without a FD, so it doesn't really bother me. YMMV.

I only suggested it because the Varsity one is a spot welded one piece chainwheel, no?

Yes it is a one piece crank.

If the chainring has good deep teeth and no ramps or pins it will probably be OK without the derailleur. Size your chain properly and give it a try.

It will work without a FD. If the rear Dr spring is still strong and has pull back, it should keep the chain taught enough.

If if keeping the FD, lose cable and shifter. Adjust throws to lock it onto the chainring you want to run.