Etched brass or brass tubes for boilers.

[Kits from Somerset]

Well looking at some of the Blacksmith engine kits and they need brass tubes for boilers so stick with this or go for etched brass ones in stead.

 

Etched brass boilers.

 

Disadvantages.

 

Have to be rolled.

 

Can be a bit thin if etched so they include the boiler bands in place.

 

Advantages.

 

Boiler bands in place.

 

Holes in place for dome, handrail knobs etc.

 

Brass tubes.

 

Have to have the boiler bands added to it which will have to be marked out to be in the correct place.

 

Holes will have to be drilled out for the handrail knobs etc.Not very easy.

 

Advantages.

 

Stronger.

 

Don,t have to be rolled.

 

So what do you think will be best to do ie a new etch for the boiler firebox or stick with the brass tubes in stead.

[jamie92208]

I've used both and had good results.  however the Slaters 7mm kits that I've built have their boilers turned from thick walled brass tube and they include the boiler bands.  You just ahve to add the smokebox wrappers.  The advantage is that there is plenty of built in weight to the loco which helps with adhesion.  Some kits that I built used thin walled brass tube but not of the correct diameter so I had to slit it and put an insert along the base of the boiler.  Etched boilers can easily get misshapen. 

 

Out of the three I prefer the turned thick walled tube but there arn't many kits on the market like that.  After that i would go for the brass tube rather than the etch, as long as it's of the correct diameter.

 

Jamie

[Horsetan]

You're lucky that none of the Blacksmith loco kits have tapered boilers...

[Jol Wilkinson]

Eched are better, correct size, holes for boiler fittings, clearance cut-out for 00 wheels, etc. You can easily provide them already rolled, not a big problem with a GW or similar rolling mill. Don't bother with boiler bands, they are only 1/8" thick on the real thing and best represented by waterslide transfers (or paper strip for plain black livery). Etched boilers, being thinner material are also easier to solder. Strength isn't an issue, an etched .012" brass boiler when soldered along an overlap joint seam is pretty robust.

 

Tubing is okay for simple boilers, e.g. tank locos but need marking out, drilling, etc. Not the best option.

[Kits from Somerset]

You're lucky that none of the Blacksmith loco kits have tapered boilers...

 

But you will never know what will happen at a later date.

[Horsetan]

But you will never know what will happen at a later date.

True. In which case, a plain tube won't help you. It would have to be properly drawn on the flat, then rolled.

[Siberian Snooper]

I would have thought that an etched boiler would have several advantages, in that it can be the correct final diameter or taper the positions for the dome, top feed, safety valves, clacks etc. will be in the correct position and soldering to the smoke box and firebox will be easier as there will be less brass to heat up.

 

SS

[Horsetan]

I would have thought that an etched boiler would have several advantages....

Certainly does.

 

The plain parallel brass tube has been around for decades, but technology hasn't yet produced a ready-made tapered one. That may be because angles of taper are so many and varied.

[benachie]

The strength of brass tube for me.

Alan

[ozzyo]

Hello all,

 

both types of boiler have there pulses and minuses.

Etched pluses, correct size (if drawn correctly).

Etched minuses, all of these are if drawn wrong, the holes can be in the wrong position, over thick boiler bands these can also be in the wrong position, thin, has to be formed (if preformed not always correct).

 

Tube pluses, strong, it is round.

Tube minuses, not always the correct size, you have to drill the holes (but this can be better, see above) no boiler bands (see above).

 

In both the above you can see that both have pluses and minuses, but does one come out as a winner?

Both of them are light, so you have to add weight. Looking at it I would say that a good quality cast boiler should win all of the time.

 

OzzyO.

[Dorsetmike]

I work in N gauge and turn my own boilers from tube, so far only smaller  Drummond and Adams locos, so no problems there with taper boilers - yet!!

 

For larger locos and taper boilers up to now I've been able to either kit bash  or hack RTR. (eg Lord Nelson from Peco Jubilee or BachFarish Scot with Minitrix tender drive, or Union Mills drive with an added axle)

[Jol Wilkinson]

You have to see this from both a manufacturer and a model maker point of view.

 

By designing your own etched boilers you are in control of the item dimensions, etc. and can order as required.

 

By using tube boilers you are dependant on supply of the correct size - which I know from experience can be erratic. If turning the boiler to length (a must in my view, especially as it ensures that the ends are "square"), then you may be reliant on another outside provider, more opportunity for problems/cost.

 

Although I have built kits with both tube or etched boilers, I prefer etched, with holes, etc already made/marked. I don't see the strength issue at all provided the boiler etch is full thickness, not half etched - see my previous post re boiler bands, the only reason to half etch a boiler AFAIK - unless you are especially ham fisted.

 

Cast resin boiler/smokeboxes are another option if starting the design from scratch, but even these have some design/manufacturing/building drawbacks.

 

Jol

[Kenton]

I can only think of one advantage for brass tube an you didn't list it - weight. Sorry etched every time. rolling is not the issue many make it out to be and brass tube always seems to end up looking like - plain brass round tube. Surely we have progressed a little from the scratch building compromises of the 1970's?