Soldering larger silver object

I am assisting a model maker in making a 1/72 scale Hawker Hurricane
(WW2 fighter) in sterling silver and have got to the stage where we
need to solder the two fuselage halves together. Since this is bigger
than my normal items and there are hundreds of hours work in the
fuselage I really don’t want to melt it! My choices seem to be to use
my enamelling kiln (poor temp control) or a big flame on a pumice or
charcoal bed to retain/reflect some heat. Any ideas/ suggestions
welcomed. It is fabricated in 0.8mm sheet and we want to use hard or
IT solder to allow for 2 further large solderings - wing assembly and
tailplane.

BTW the experience of assisting Brian who has 40 years of model making
but no silver experience has been most rewarding - a real two way
learning experience.

Andy Parker, Agate House Lapidary
Ulverston, Cumbria, England
@Andy_Parker

Tel: 01229 584023

Andy, I do not know how large this thing is but I think the most
important variable is warping, not necessarly melting. I would suggest
using a mid gauge(14-16) binding wire to tie the wloe thing up with
equal tension around the whole thing. If you are going to solder with
a torch try building a fire brick structure around the item and
pre-heating the bricks. Although I have never soldered in a kiln
before, I have heard of good results, and it seems that a small (.5
to1mm)amount of warping is innevetable.

Godd Luck,
Todd Reed

Hello Andy,

I do not know how big your torches are but you need a big gas burner
to heat a whole surface or you can use a gas/oxygen burner for steel
sheets 1-2 mm, and heat partly and solder partly. This is what I
prefer and now is the safest way… Be careful when you heat partly,
that your work is not bending by heat or moving. Position and
tightened the part good together with wire. Than solder first in the
middle a few millimeters than the other side a few mm. Than a spot on
the front and the tail. When everything is in the correct position
fixated. Solder the rest from the middle to the tail and the other
side, from middle to the tail . Work symmetrically .Use a lot of
borax or degussa H. This helps good to flow the solder. Do not solder
in the sunlight you get difficulty in seeing the glowing silver. If you
find trouble in heating up you can build from Yton blocks (foam
concrete) some walls. I use these blocks always for soldering they are
cheap, you can easy scrape a shape in it and reflect good heat.
However they will melt a bit when using gas/oxygen. But if they are
dirty take a new one. I think you will succeed in this project 0.8 mm
is thick enough to have some tolerance is mistaking.

good luck
Martin Niemeijer
questions?
@Martin_Niemeijer