I am stoked, I'm picking up a used 6m LQ session this afternoon.
Anyways, anyone made a buggy or beachboard/ mountainboard using wheels that are from hand carts?
The ones in the 9" range".
Harbor Frieght carries these at a good cost.

Been there done that on a buggy. The cart wheels that have a single weld on one side of the hub are "NG" that is no good. You would have to put a heavier weld on the welded side and add a weld to the other side to make them usable otherwise the scab on them from the factory is good for about 3hours of side loading. Even then they may not hold up d/t the thin material thats used. A board may hold up better having smaller diameter wheels, may flex less and may not experience the side loads that a buggy puts on them. 4 of them on a board though could be pretty heavy.
Home Depo carries wheelbarrow wheels plastic with ballbearings $25 or you could hold out for some used ones on PKF.
Welcome to the forum , also check Popeythewelder site.

at a minimum ,you should get the 16" wheelbarrow wheels . Then knock out the low speed bearings and replace with sealed 1-3/8 x5/8 precision bearings the ones w/ a snapring. I have used them for several years,then I got the alloy bling rims w/ 18.5x8.5x8 kenda multiribs.They are way better!

Thanks, I will be checking on those options.