What do you guys use this for, as a top coat or as sealer or can it be used for both?

I can be used for all the above.   When used for a sealer I like to thin it will some denatured alcohol so it soaks in the wood better.   Prefer the 5min for installing my hardware.

Devcon 2 Ton - the Swiss Army knife of crankbait building!  I use it for everything -

undercoating, gluing in hardware, topcoating.

Thoreau:  "Simplify, simplify, simplify".  Me:  if you want simple, just say it once, OK?  But D2T gets the spirit of it.

I think Bob will agree with this.   Devcon 2ton is the simplest product to use for newbie getting his feet wet.

Would 30 min work? its the only one I can find. Also would I be able to use half of it to seal and the other half as a top coat or is it use once and done?

You want to use the 30 minute. The 5 min. will cure too quickly if used as a topcoat

I think Bob will agree with this. Devcon 2ton is the simplest product to use for newbie getting his feet wet.

Big M, what do you use for topcoat on the cranks you build?

Devcon 2 Ton is 30 minute epoxy glue. That just means it forms a glue bond in 30 min. When used as a topcoat, it takes about 5 hrs to cure hard enough to handle and it reaches full cure in about 24 hrs at room temperatures. When you brush it on as a topcoat, you have 3-4 mins before it begins to harden, so don't waste time. If you measure accurately and mix it really well, it is the most foolproof epoxy to use. For topcoating, you can mix in a few drops (and I mean only 3-4) of solvent like denatured alcohol or lacquer thinner to make it a little thinner and extend the brushing time a couple of minutes. For undercoating, you can mix it up to 50/50 with solvent so it penetrates and protects the raw wood. Devcon is a great epoxy for first time users because it's simple to use, levels out well over surface defects, and yields an attractive, durable topcoat with one coat. Using a lure turner after application is best but it's thick enough and cures quickly enough that you can manually rotate the bait for 40 minutes and get good results. I have put hangers on the nose and tail, then switched it up/down every few mins for half an hour and gotten good results. Quite a few custom builders use it on all their baits, so saying it's "good for newbies" doesn't imply it isn't great stuff. One 30 ML double syringe is enough Devcon to undercoat, glue in hardware, and topcoat several bass baits.  There are other products, of course, but they all require more equipment, application knowledge, expense, and storage care than Devcon.

I think Bob will agree with this. Devcon 2ton is the simplest product to use for newbie getting his feet wet.

Big M, what do you use for topcoat on the cranks you build?

i dont know for sure but ill bet you its not devcon big m uses for his top coats