Normal if the oil is very cold. Not normal if you have brought the welder and oil up to temp first. I like to drain them cold, but I let them set over night. Hot oil should drain out in a minute or so. If oil additives have been put in the oil it could drain real slow.
We had one engine come in the shop and the oil was as thick as grease. engine had to be replaced. The theory was an additive was put in the oil and then the engine was over heated some how and the oil turned to jello.

 

I warm mine up and change it every 50-100 hours depending on where I am working and how hard the machine has it. When it is cold it takes forever to drain.

 

Doesnt sound normal even for cold oil to me.

 

I drain It warm and also open up the dipstick it helps vent it and it drains agood bit faster.

 

When I changed the oil and filter it was cold out. Probably 40* here last week. And the machine hadnt been running that day.

I also took off the filler cap to achieve Atmospheric Pressure but that didnt have any effect. Glad its just not my machine that drains slowly.