Homebrew PCBs

> My application is OT.  It is a very large photographic wet bench -
> about 86 x 54 inches - and I am prepared to use glue if necessary but I
> would rather master the welding if I can.  I have got to get something
> out of my expensive hot air gun!
>
> Thanks again for the help...
>
>
> Simon Whitehead
> s.whitehead@...
>

Try look in the archives, there was one very good description of the 
different
methods, how to hold the things and so on. (a link to pdf i think).

I too have this gun, it is the best one i think. the new model is a 
downgrade again,
it has gone back to using a few leds for display, the control circuit 
seems the same.
be aware that the degree reading is inside the heating chamber, but there 
fairly
accurate. i measured once and if you put the probe exactly where the air 
comes out
through the slots it is correct with my gun.
looks much different a inch away already.

There are LOADS of useages for this tool, it is worth the money.

The trick is the control circuit. If you compare tools with closed loop
control circuit (electronic and accurate) to tools without they are worth 
way more
than double the price. i had a cheap air gun (eur 20 or so) before, it was 
really
useless.
It's the same with other tools. If you compare a power drill with real RPM 
feedback
control circuit with a power drill without you will see the differences.

If you ever design some machine try to implement a good control system.


Always let your gun blow a few seconds on cool, or the first notch of the 
switch
after high temperature, and put it standing on it's back so the heat rises 
up.
Once i forgot that and suddenly there was already smoke coming out.
the hot ceramic body heated some air, which was not forced forward and out 
any more,
and this air obviously went back into the plastic parts. there is a plastic
fan wheel and stuff which you definitely don't want melted.
there was no visible damage then but now i always put it vertical and let 
a few seconds cool
air through. (i guess the manual would recommend to do that but you know, 
i didn't read it..)


I have not yet mastered welding, i tried on a few different plastics, abs 
was the worst
and didn't work at all. i have not bought the welding shoe yet and so i 
tried the method similar
to acetylene torch welding, well, it does not work as good as acetylene 
torch welding...


I also do some soldering with the gun... if you want to solder together 
two wires
or solder on a connector it is sometimes easier than a soldering iron.
the advantage is you have no contact, only air.
In my opinion it is a "must have" tool.


Good luck with the welding!
And keep in mind some materials are easier to weld and bend.
i had some older plexiglass which was impossible to bend before getting 
blisters.


ST