The Shop > Our Shop

Fire In The Foundry

<< < (3/3)

awemawson:
This morning I started stripping off the left hand side of the timber cladding. It's a very awkward corner, and if I wasn't left handed would be pretty well impossible - luckily I am !

The bulk is now removed and the finessing begins - all those plank ends need trimming in situ back to the wall which should be possible with the Fein Multi-tool but it only just gets in the space behind that RSJ.

Up at roof level the construction gets complicated to say the least - this is where three buildings and their roofs come together having been built at different times, and not surprisingly is where I have had an ongoing persistent leak when the wind is in the wrong direction.

I'm not as flexible as I'd like at the moment so enough for just now - but at least it's a bit of progress. The blue vapour barrier was fixed to the unclad original barn that forms my workshop, and once clad with shiplap had foam insulation sprayed from the inside. That foam, though not particularly inflammable, is not fireproof but it's not really feasible to remove it - I will probable over clad it with fire rated fibre cement sheeting, and seal the edges with fire rated expanded foam.

awemawson:
So after what seems a ridiculous amount of time I eventually got the rest of the original timber shiplap cladding cut back and was able to start boxing in the exposed inner wall that has my workshop on the other side.

So what to use to box it in ? I happened to have two sheets of Knauf Aquapanel that is intended as a tile backer board. Knauf claim it to be fire resistant as well as suitable for damp conditions. A quick test with a propane torch showed that indeed it was fireproof, and as this corner is the one with the irritation of occasional  roof leak it seemed be the stuff to use!

The placing of the original batons wasn't the ideal spacing but the wall construction didn't allow of change so they were re-used. Firstly running a 2" border round the periphery I then cut the lower panel to size (9" diamond saw and loads of dust!

The second panel wasn't so simple having the slope of the roof and some odd cut outs so I first made a plywood template before slicing up the remaining sheet of Aqualpanel.

The complex construction of this corner offered a few challenges - the welding shop next door has a 100 mm block cavity wall spaced off a similar shiplap wall that I'd had built years ago to prevent fires, but this cavity was exposed to the foundry where the RSJ's had been welded and bolted to form the new foundry building. Very little to fix cladding to here and I resorted to bending up a metal box structure to make the necessary seals.

awemawson:
Then it was a case of squirting fireproof expanding foam into all the joints. I hate applying this stuff! One of the main problems is that the can has to be inverted when spraying, and if you are filling the roof / wall joint this is neigh on impossible. For the first can I added a pipe extension but up in that tight space, on a ladder and reaching round the RSJ it was never going to go smoothly !

First can did about 3/4 of the job, and I had intended to trim the surplus foam back and make good missing bits with the second can. Despite claims as to 'time to trim' on the can they weren't realised so I carried on as best I could after a few hours filling in the missing bits.

As always in this situation far too much ends up on the floor - and as it finally all expands and set much will have to be trimmed back for tidiness - I guess somewhat less than the volume of one can will actually remain in the joints !

So apart from trimming the foam, I still have to re-fix the electrics and scrape mounds of set foam off the floor then I think it's 'job done'.

. . . did I tell you that I hate expanding foam !

awemawson:
So you'll be pleased no doubt to hear that this long drawn out mini project is finished. Several days ago I trimmed back the 'fireproof' expanding foam and re-routed the cables for the light switch and pair of twin sockets.

These cables are 'Hi-Tuff' circular with an 11 mm diameter outer sheath and I had no suitable cable clips for them - clips ordered and at last they arrived this morning and were fitted. Previously these cables were routed (clipless) behind the shiplap cladding that I've removed.

So foundry now back in use - in fact I did a couple of melts yesterday one of which produced an amusing incident. I was reducing an old rotating washing spinner to ingot - it comprised channel extrusions and the main central tube that sits in a hole in the lawn. Extrusions went in first to produce a nice molten puddle, and then a 12" length of the 2" tube. As I reached down to get another tube length from my bucket the first one was ejected onto the floor  :bugeye:

Trying again sure enough the tube was levitated ! No big issue - I just held it down with my poker until it melted.

I assume that the tube being a complete circle had sufficient magnetic field induced in it to react with the furnace field and hence levitate - it WAS a bit of a surprise !

For neatness I do still need to shorten the mains cables for the roller shutter door and emergency light fitting that plug into that upper double 13A socket but that's trivial.

tom osselton:
I would not have thought that it could levitate like that!

Navigation

[0] Message Index

[*] Previous page