'evening

[gerry hattrick]

Some years ago a granddaughter called me a a geriatric, so I used the title for eBay etc.

I've owned a SIP welder for more years than I care to remember. It gets spasmodic use and has let me keep several vehicles running past their normal expiry date. It broke down a few years back and a bought a Gas/Gasless one from Northern Tools, but it didn't seem to be as flexible as the SIP. It turned out one of the reed switches on the SIP control panel had burned out. SIP wanted £150 for a new panel so No. 1 son swopped the faulty part with a reed swith from a function that wasn't used.

Our main problem is getting gas. BOC have just lost their local agent and are suggesting I make a 220 mile round trip when I need a replacement bottle

If that is the best they can do then I can see that I will have to persevere with the gasless welder.

The present project if the restoration of our 1988 camper van, a Ducato diravative. One of the many faults with this vehicle seems to be that it was designed for salt free roads, I'm told that there many good examples all across N. Africa. They were made with many large holes in the inner sills to allow access when built and these naturally rot quite quickly if the first owner is not aware of the potential problem. Anyway one side has been completed and the offside is well underway so hopefully the 'van will be on the road agin in the Autumn.

Apart from that the welder is used by No. 1 son mostly on his car and it got a lot of use when he converted a Beetle into a Buggy.

I've been looking at the use of MIG for building pressure vessels. Some 'authorities' claim that they should be avoided because the weld pool might be slow developing, unlike TIG, which could result in poor penetration. I'd have thought that an answer to this would be to start the arc a short distance away from the prepared join and to move to the regired location once the arc was established. Anyone any comments?

Dave Ball (Fort William, Highlands)

 

[malcolm]

Hi Dave, a late welcome to the forum (I missed your post the other day).

Have you tried the dealer locators for BOC and air products? Looks like there's a caravan park in Fort William that might supply airproducts CO2. Maybe they can be persuaded to get some other stuff in too.

http://www.boctradequip.com/
http://www.airproducts.co.uk/cylindergases/locator.htm

Otherwise what do the garages do in your area? There must be someone with a delivery round.

Not sure about pressure vessels - that's the sort of thing I wouldn't like make, and I'll bet there are all sorts of regulations to do with welding them. A possibility could be start the weld, move the gun forwards and then back again over the work you've just done.

 

[gerry hattrick]

Gas Supplies

'Morning Malcolm

Thanks for the info. There are several possibilities for getting cylinders. At my rate of consumption gas costs about £80 per year (1 refill = 2 years rental).

You are right about the regulations concerning pressure vessels. My interest is in the construction of small boilers for miniature steam locomotives. These are not covered by formal regulations because of their small size and because they are not built commercially. A boiler that costs say £100 in materials costs £1500 when built by a boilermaker.

There is a voluntary code recommended by the Dept of H & S that is administered by groupings of Model Engineer Societies. To conform the part built bolier is inspected and then the completed boiler is inspected and subjected to a hydrostatic test. There is nothing to stop a builder doing his own test before bothering the society and getting the boiler certified.

Regards

Dave Ball

 

[Hitch]

I dont know about the regulations for small vessels, but usually must be welded by a coded welder to a set procedure.

What size boilers are you looking at then?

I must admit, i would favour tig for small boilers due to increased control, shouldnt be much chance of fusion problems.

As for the mig not starting, as long as you grind out your stops and starts and get it set properly it shouldnt be a big problem.

 

[gerry hattrick]

Small Pressure Vessels

Hello Hitachimaid

The boiler size will be of the order of 18" long by 5" dia. There was a write up on test requirements in the last Model Engineer. Although I forget for the moment the exact volume that triggers the need for formal annual insurance inspection I do recall that a boiler 24" x 6" is not too big for the less rigourous test. Having said that full size locos also steamed at 2 to 3 times the pressure of the boiler I am contemplating and in %age terms did not have to be tested at twice the working pressure. Certainly a local builder has constructed a boiler for his 4" scale traction engine using steel and had no difficulty getting his work approved.

Regards

Dave Ball (gerry hattrick)