Model Boat Mayhem

Technical, Techniques, Hints, and Tips => Engineering Techniques and Materials. => Topic started by: flag-d on April 26, 2006, 10:42:43 pm

Title: 'structural' soldering made easy(ish!)
Post by: flag-d on April 26, 2006, 10:42:43 pm
Having spent hours accidentally de-soldering 1 part while trying to attach another, here is what I came up with...

Aluminium is the key to this.  I had to make up some girder-like brass supports for parts of my MTB: brackets and struts, uprights and diagonal braces, so I sat and pondered a while.  I used a piece of thin aluminium plate as a layout plate and laid all the parts out on this.  I then drilled various holes in the plate and through into the bench top too (deliberately this time!).  Into these holes I pushed one end of L-shaped aluminium wire pieces.  These were bent slightly over 90? so that as they were pushed in, they 'locked', the bent over bit holding the brass part down onto the base plate.  Like this, I could hold every part in place (17 per support in this case), quite securely.  Apply plenty of flux, then heat, then solder.  The beauty is that the solder will NOT stick to the ali plate and wires, not at all, not even a tiny bit!  Using the ali wire to hold the bits in place makes it so easy too.  For the ali wire, I used 2.4mm aluminium TIG welding wire (because my work had some!).  You might find your local garage/welding shop might let you have a few pieces.  You can re-use them over and over.  I used to hate this sort of soldering: getting 2 pieces joied together perfectly, then watching as they fell apart before I'd even got the 3rd one in place!  Now I look forwards to it...almost!

I think I have a couple of pictures somewhere which show the idea a bit better than my waffle explains it.  I'll have a look.

Happy Soldering ;D

Mike
Title: Re: 'structural' soldering made easy(ish!)
Post by: flag-d on April 27, 2006, 05:35:59 pm
I found a picture...

Mike



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Title: Re: 'structural' soldering made easy(ish!)
Post by: warspite on September 27, 2006, 08:12:02 pm
Here's a point, in order to do multiple joints in such small fabrications, how do you isolate the heat transfering through the material and releasing the joint you just finished or one elsewhere in the assembly. ???

Title: Re: 'structural' soldering made easy(ish!)
Post by: wombat on September 27, 2006, 08:59:38 pm
I was always taught the secret of a good soldered joint is a good mechanical joint. Of course this is not always possible. To stop joints coming unsoldered as you move around, the secret is to be quick and to avoid disturbing the piece. You could try clipping on a heat shunt (e.g. Maplin FR10L). As an alternative get a drop of water or a damp cloth over the made joint - this should slow the heating of the made joint. If you can get a drop of water over it, you can see when it is getting too hot because the drop boils away.

Tim the Wombat
Title: Re: 'structural' soldering made easy(ish!)
Post by: barriew on September 28, 2006, 01:49:05 pm
The other solution is to use different melting point solders - Paul Freshney describes the technique in the October MB.

Barrie
Title: Re: 'structural' soldering made easy(ish!)
Post by: cbr900 on September 28, 2006, 02:02:50 pm
MIKE ,

That is a very good idea and one I will certainly put into practice, thank you Mike well done...



Roy
Title: Re: 'structural' soldering made easy(ish!)
Post by: chromedome on September 28, 2006, 02:14:35 pm
 Wombat,s the simplest so it will do me ;)

   chromedome
Title: Re: 'structural' soldering made easy(ish!)
Post by: White Ensign on September 28, 2006, 04:03:06 pm
I use to fix them on a aluminiumplate with a little drop of superglue, solder them and then weaken up the superglue with aceton. Or put it all together in a pot with boiling water- it will clean the brass from any soldering agent and also gets the superglue off.

Jörg

P.S.: But the idea of the fixing joints got me started.....hmmmm- need to have a go into the workshop.....
Title: Re: 'structural' soldering made easy(ish!)
Post by: 2772e on September 28, 2006, 04:04:29 pm
I used to hate soldering but following a local trip to a good quality motor factor, not your high street boy racers outlet. I managed to buy liquid solder instead of flux. I thought i would give it a go anyway.

Stick the items to the bench, put the liquid solder on to the joint with a small paintbrush, heat briefly and hey presto, no mess, 1 spare hand and a lovely job.

Have not looked back since.

 ;D
Title: Re: 'structural' soldering made easy(ish!)
Post by: chromedome on September 28, 2006, 06:51:31 pm
do you have the trade name for the liquid solder please?

 chromedome
Title: Re: 'structural' soldering made easy(ish!)
Post by: 2772e on September 28, 2006, 07:03:27 pm
Taskmaster Solder paste from Partco/Brown Brothers. Am i allowed to say that?

Soldering will never be the same again

Enjoy
Title: Re: 'structural' soldering made easy(ish!)
Post by: krfilby on October 02, 2006, 07:10:51 am
Does anybody know of a UK site where I might purchase some of this solder paste ? Had no luck with Partco/Brown.
Regards  Keith
Title: Re: 'structural' soldering made easy(ish!)
Post by: cbr900 on October 02, 2006, 08:01:05 am
Cannot find any over here either, seems as if it is a bit on the hard to find side...


Roy
Title: Re: 'structural' soldering made easy(ish!)
Post by: DickyD on October 02, 2006, 10:31:52 am
Theres loads about it on Google though not that particular one.

Partco/Brown is part of Unipart.

                                                 Richard ;D ;D
Title: Re: 'structural' soldering made easy(ish!)
Post by: flag-d on October 02, 2006, 12:35:15 pm
Stopping already soldered joints from remelting:

Magic!  That's the answer!  Well, maybe not, but that aluminium back plate acts as a very good heat-sink and seems to take away a lot of the heat.  I always use bent ali wire pieces to hold everything in place, which a) helps with heat transfer to the backing plate and b) holds the parts in place so if remelting does happen, its not disastrous (entirely!).

Solder-paste:

I haven't used any for years now, but I used to have some which I 'borrowed' from work.  At that time my work place got most of it's soldering/electrical/electronic bits from RS or Farnell.  I know you can buy direct from RS on-line, but Maplins may sell much the same stuff also.  It was a small tin, like a boot polish tin and probably hideously expensive, but it was jolly good stuff.

Mike
Title: Re: 'structural' soldering made easy(ish!)
Post by: 2772e on October 02, 2006, 05:38:40 pm

Here's the number for my local branch, this is where i got it. They should be able to mail order?

01245 281244.

Regards

Simon

 ;D
Title: Re: 'structural' soldering made easy(ish!)
Post by: cbr900 on October 03, 2006, 12:30:39 am
Mike,

Tried your idea yesterday worked perfectly thanks mate, will continue to use it...


Roy
Title: Re: 'structural' soldering made easy(ish!)
Post by: krfilby on October 03, 2006, 07:44:01 am
Thanks Simon,
Finally located the solder paste at  http://rswww.co.uk.
Keith
Title: Re: 'structural' soldering made easy(ish!)
Post by: barriew on October 03, 2006, 11:43:46 am
Thanks Simon,
Finally located the solder paste at  http://rswww.co.uk.
Keith

Better make that http://rswww.com

Barrie
Title: Re: 'structural' soldering made easy(ish!)
Post by: badbunny on October 04, 2007, 09:07:56 pm
Sorry, I can't quite visualise this clamping plate without the picture.  :(
Has anyone got a copy they could repost please?

Thanks, Pete.
Title: Re: 'structural' soldering made easy(ish!)
Post by: Bryan Young on October 07, 2007, 07:29:02 pm
I was always taught the secret of a good soldered joint is a good mechanical joint. Of course this is not always possible. To stop joints coming unsoldered as you move around, the secret is to be quick and to avoid disturbing the piece. You could try clipping on a heat shunt (e.g. Maplin FR10L). As an alternative get a drop of water or a damp cloth over the made joint - this should slow the heating of the made joint. If you can get a drop of water over it, you can see when it is getting too hot because the drop boils away.

Tim the Wombat
I was taught that a slice of potato over the joint you wanted to save acted as a good heat-sink....always works for me! BY.