Today’s adventure into sandblasting!
The hull for the new UWE SAUC-E sub is made from a fire extinguisher however in order to be welded to we first had to strip the paint from the outside. One of the team had access to a sand blaster and we decided this would be the easiest way to get this done.
So apparently its harder that it looks. never used the sand blaster before but after some basic training I got to it. Nearly an hour and a half we had still only managed to remove about 1/4 of the paint 😦
We decided there must be an easier way. One of the staff at the workshop suggested burning the paint off and then using the sand blaster just to clean it up afterwards. Only problem was that the fire extinguisher contains a waxy plastic coating inside to protect the steel. This is bonded to the inside and we would have to remove it for welding anyway. We decided to give it a go and hope that heating also freed up the insulation so we could remove it later.
After heating we tried to move the extinguisher, only to find that the inside coating had melted. It left a think putty that had a similar texture to bread dough. Dunno what this stuff is but it was horrible.
Some of the gunk was still inside and once it cooled and we could not remove it. the sand blaster would not even touch it. We decided to take it outside and reheat the metal to melt it then burn it off.
This worked relatively well and only a powdery residue was left after the fire died out. Once cooled it was returned to the sand blaster for a clean up, remaining paint just fell of and a day long job became a 20 minute job.
I was very impressed with the end result. didn’t think we would be able to remove the inside plastic so cleanly. Once we had finished the inside looks as nice as the outside.
good days work, got something done and learnt to use a new piece of equipment. Wish every day was this productive.