Stuck on this one..

[ajs]

Precisely what kind of issues are you having? If you can try and describe the problem it would help diagnosis.

What kind of iron are you using and what bit? I recall there was mention earlier of filing bits down, I must admit I grimaced when I saw that - modern bits are invariably iron plated to stop the bit bronzing (copper from bit and tin from solder) which creates a truly awful surface to solder on. If you see the solder beading on the tip that's a bad sign.

As for technique yes blutack, modelling clay or similar is what I'd use for positioning. If I was really having difficulty I'd probably consider a jig of some sort, probably starting with a jig to hold the rungs and a U-shaped side to do the first side, obviously trim ends of the side off after.

You will want a reasonably refined technique doing this, you want to work quickly especially with brass so the heat doesn't transfer to and melt neighbouring joints - if the joint hasn't formed in a second or two remove the iron and let it cool before considering how to go forward.

General soldering tips: everything to be clean before starting, components, bit and iron. If you don't have a soldering sponge to keep your bit clean a damp piece of scrap denim makes a reasonable substitute. Apply a small quantity of solder to the bit before it touches the joint, that isn't the solder to form the joint per se but forms a 'bath' for the joint to sit in for effective heat transfer. Feed extra solder in from the opposite side of the joint to the bit to supply extra solder and fresh flux.

I would strongly prefer fresh, cored, fine gauge solder for this but working with what you have I'd experiment with applying flux to either the solder or the joint prior to soldering. Even if your solder is cored to start with - the shelf life of cored solder is good but not infinite.

Final point I'd consider is unique to this kind of work. Most pliers will leave a vee edge on both sides of the cut, some side cutters are orientated differently and one side is much flatter, you want that on the end section to be soldered. If you don't have such a pair of cutters square off the end using a needle file, grinding disc in a Dremel, or even the side of a fine sharpening stone - yes the gap to be filled created by the vee is smal but it's large compared to the desired size of the joint.

 

[Kittyhawk]

The big hole in the middle is 4mm, the pins 0.15, done with rodico which is essentialy watchmakers blu tac, as per the earlier illustration.

0.15mm? Incredible! How would you feel about building me a couple of ladders?

Precisely what kind of issues are you having? If you can try and describe the problem it would help diagnosis.

No problems as such. It's just that I've never done anything so fine before. So the issue is that I'm trying to condense years of experience that I see here with other people's soldering work into an hour's work of practice.

 

[Fergie 307]

Ajs makes a very good point regarding the cut ends. I suppose I took that for granted. I hold the cut wire in smooth brass jawed parallel pliers and either use a file or wet and dry wrapped round a lathe tool. At 0.8 you might even be able to make a groove in the end for the upright to sit, try folding a piece of maybe 600 grit wet and dry in half. The folded edge will make a very fine file. His point about grinding tips is also fair comment, although I have a number of them I have ground to particular profiles and not had a problem with them just depends on what they are made of I suppose, but in an ideal world yes buy a smaller tip. If you were going to do this regularly then a proper soldering station is a boon, but very expensive for a one off job. I don't think it is really applicable to what you are doing but another technique is not to apply the solder with the iron at all. For some jobs I just cut a tiny flake of solder off with a craft knife and place it where needed, having first applied a tiny amount of flux. Then just apply heat with the iron next to It and the solder flows where the flux is. This is ideal where you are soldering a fine pin into a hole for example, and don't want the solder spreading out over the surface.

 

[pe2dave]

One thing that's becoming obvious from the many helpful replies is that there is a bit more to soldering than meets the eye.
Firstly, I've have taken Fergie 307's advice and spent my 6 bucks on the 0.5mm brass rod and damn the expense.
Secondly, beginning to doubt the solder and flux that I have as to their suitability for this delicate work. I found the two reels of solder in a second hand store, the black reel is 2.3mm dia solder and has 'Capalloy' on it. The red reel is 1.6mm dia solder and is unnamed. The bottle is just some hardware store generic flux. Do I need something more specific for what I'm trying to do?

Suggest you look for solder with flux 'built in' (capilliaries I think). For .5mm stuff, finer solder the better?

 

[Richard_C]

It's always a struggle to solder when you have 2 separate things, solder, an iron and only 2 hands.

I might approach this by cutting 4 lengths of rail, too long, and fixing them to a board (MDF, card, whatever) so each pair is the right distance apart and there is a gap between pairs. Fix down using tape at the ends. Then put the rung material over all 4 of them, again cut too long and taped down around the perimeter. With your grid firmly in place, dab some flux on each joint and quickly solder with iron in one hand and reel of solder in the other. Then cut it up, all to length, and tidy up any blobs with a small file. That way you are not juggling tiny things that want to move as you work. The top on the card becomes the back in the final assembled model.

 

[Fergie 307]

Having thought about it some more, and the issue of having to get all the rungs in the same orientation i would suggest getting a small piece of square section wood, a matchstick would do. Stick two pieces onto a bit of card or wood so they are in line but with a gap between big enough to get your iron in. Lay the upright against the stick and postion your rung opposite the gap. Apply heat to your previously tinned upright through the gap to make the joint, move upright along and repeat. Once you have done one side flip it over and do the other. That should work. If you have problems with the heat spreading i should think a strategically placed wet q tip or piece of tissue will solve that one. Try doing it with just the tinning, you really shouldnt need to add more with wire as fine as this. Important that all the ends of the rungs are nice and square ended, and the same length. If you do need to add more then dont do it with the iron, just shave a bit off the solder wire with a craft knife and drop it on the joint with tweezers before you apply the heat, you will only need the tiniest piece.

 

[Kittyhawk]

Having thought about it some more, and the issue of having to get all the rungs in the same orientation i would suggest getting a small piece of square section wood, a matchstick would do. Stick two pieces onto a bit of card or wood so they are in line but with a gap between big enough to get your iron in. Lay the upright against the stick and postion your rung opposite the gap. Apply heat to your previously tinned upright through the gap to make the joint, move upright along and repeat. Once you have done one side flip it over and do the other. That should work. If you have problems with the heat spreading i should think a strategically placed wet q tip or piece of tissue will solve that one. Try doing it with just the tinning, you really shouldnt need to add more with wire as fine as this. Important that all the ends of the rungs are nice and square ended, and the same length. If you do need to add more then dont do it with the iron, just shave a bit off the solder wire with a craft knife and drop it on the joint with tweezers before you apply the heat, you will only need the tiniest piece.

Thank you for the effort you are putting into my project. I appreciate it very much.
The courier says my lengths of 0.51mm brass rod will be delivered today so enthused to start with the job.

 

[Fergie 307]

Dont tell Mrs Fergie, but i find a good base is a hard glazed white plate. Allows you to see what you are doing, and impervious to the heat, solder etc. You could stick the sticks on with hot glue or PVA. Will hold well enough, but still easy to peel off when the plate needs to go back in the cupboard

 

[Fergie 307]

Suggest you look for solder with flux 'built in' (capilliaries I think). For .5mm stuff, finer solder the better?

That is an interesting point. Some solder has a single flux core in the middle. This can be really useful as if you cut a thin slice off it what you end up with is a small washer of solder, ideal for passing over a small shaft or pin when you want to precisely apply a very small amount.

 

[Fergie 307]

Thank you for the effort you are putting into my project. I appreciate it very much.
The courier says my lengths of 0.51mm brass rod will be delivered today so enthused to start with the job.

Don't be daft, interesting to think how I would approach it. I have taken great pleasure looking at all your wonderful models, as I know others have. I would have no idea how to go about what you 're able to do in wood, so if I can make any small contribution it is a pleasure.

 

[Terrytpot]

… for the hobbit market direct or through model shops. There….

I’d like to dissasociate myself from this flagrant attempt at “bellittiling” someone purely from hailing from the country where so much of the rings trilogy was filmed. I honestly expected better from you Pete..

 

[Inspector]

Good catch! Well I don't know whether you will believe me or not but I don't even remember thinking about Hobbits much less typing it. I'll blame the Spell Check and not noticing it didn't say hobby.

Pete

 

[Fergie 307]

For cleaning up you can easily make your own very fine files. Here in the UK you can get cooks matches, like ordinary matches but about four inches long. Rub the stick smooth and flat on a piece of wet and dry, then cut a thin strip of wet and dry and glue it on, hey presto a fine file. How fine just depends on the grit of the paper you use. You can do the same with lollipop sticks, or as our American cousins rather endearingly call them, popsicle sticks. If you don't already do this then it might come in handy for other aircraftery projects.

 

[ajs]

Good catch! Well I don't know whether you will believe me or not but I don't even remember thinking about Hobbits much less typing it. I'll blame the Spell Check and not noticing it didn't say hobby.

Tolkien was supposedly at Stonyhurst College when devising Middle Earth and it is based on the locality. I'm not exactly next door to the college but it's less than an hour on push bike even for me...

 

[ajs]

Thank you for the effort you are putting into my project. I appreciate it very much.
The courier says my lengths of 0.51mm brass rod will be delivered today so enthused to start with the job.

Oh right, sorry, I was under the impression you already had the brass. You should find it a lot easier to work with than steel paper clips, steel is nasty stuff to solder even if not lacquered or whatnot. Just be mindful of the conductivity - brass does get hot fast.

 

[baldkev]

K&S Precision Metals make and sell solid, square and round tube etc for the hobbit market direct or through model shops. There must be modelling shops in NZ that carry it or the same in other brands. You should be able to solder it together with plumbers solder unless you are good with silver soldering/brazing.

https://ksmetals.com/collections/brass/rod
Pete

I was right. First place in the search.

https://www.hobbycity.nz/products/k...20-x-12-5-lengths?_pos=2&_sid=cfb345def&_ss=r

As usual pete, your google_fu is on form

I cant wait to see the plane

 

[Kittyhawk]

This is a ladder of sorts, not going to keep it.
What a disaster! Dropped the half finished first one on the floor and couldn't find it - it really does pay to keep a tidy shop, and during the second one got a big telling off for the salty language which my wife assured me that all the neighbours could undoubtedly hear.
The first problem is keeping the rungs aligned to the sides whilst soldering. I tried blue tack, masking tape, small weights but the parts would always move at the critical moment.
I've got some ideas to try on that tomorrow but the main problem is with the soldering iron. I cleaned and polished the tip down to 400 grit wet and dry but for some reason I can't tin it. I squirt a bit of flux on it but when the solder goes on the tip it melts instantly but then turns into a horrible black mess that looks like soot. This sooty stuff prevents the brass from tinning properly and interferes with the heat transfer when attempting a joint.
As far as I'm concerned the woodworking part of building model aeroplanes is a doodle compared to trying to solder.

 

[Fergie 307]

Ok. I have had the same issue with soot, with one particular type of flux cored solder. I think in my case it was caused by the iron being too hot for the flux, which then effectively burns. You can experience much the same issue brazing if you overdo the heat or time with the wrong flux. Just to make sure I would try seeing what happens if you apply it to a section of the tip you haven't ground down. If it works ok there then it may be you have the issue ajs mentioned. I haven't personally had this problem, and in my case the soot formation was on an unmolested tip, and was solved by using a different flux and solder. Does your flux work ok on the brass? As an experiment try cleaning the tip, apply some flux to the brass drop a small sliver of solder on it, then apply the clean tip next to it, so no solder or flux on the iron atall. Just let the heat travel and melt the solder and see what happens. If everything is as it should be then once it reaches the correct temperature the solder should melt and spread out across the surface and become very shiny. If it forms a blob, or looks dull, then your flux is not working. Try both with and without the separate flux. And do you get the same result with both reels of solder? You can check If your solder is flux cored by cutting a very thin slice off it with a craft knife. Look at it with a magnifying glass and you will see either one core in the middle, or several like a pepperpot. Hard really to know what is going on without knowing the products. If the solder is old then it maybe if it is flux cored it is just past its best. Or it may be the flux is not correct. Given what you have managed in the face of these problems I think of you can crack this problem you will find it much easier. As to the parts moving about I am struggling. If you try and apply the tip on the joint, then the bits will move, unless you have much steadier hands than me! Indirect heat is the trick. I wouldn't expect the bits to move if held down as you describe. Hopefully if you can solve the solder issue this will help as you will only have to touch th wire for a second for the joint to be made. But looking at your ladder I think you are being a bit hard on yourself, that's pretty damn good for a first attempt, having never done anything like this before

 

[Fergie 307]

Went back to your pics and he flux seems to be made by Weldwell? Can't seem to see much info on their products, but what I can all seems to relate to flux for steel. Does it say on the bottle what it's for? Would also help to know what iron you are using, and the tip. I always use plumbers paste flux, very aggressive stuff but works almost instantly so the joint forms very quickly, just what you want for this very small stuff. It is also very good for soldering different metals, so brass to steel for example. I hit on this year's ago when I was having difficulties with getting the solder to take on a particular job. I had a tub of it bought for doing my house plumbing, and just thought I wonder if that would be any good. Have never looked back, and now use it all the time. Only caveat is you can only use it on stuff you can clean thoroughly afterwards, it's very acidic so if you leave it on it will carry on working. If you watch a decent plumber they always have a damp rag to wipe off the outside of the joints afterwards. For the tiny watch parts I apply it with either a needle or a tiny brush, then after making the joint they go straight in some warm water and detergent or alcohol in the ultrasound machine to get rid of any residue. I have no doubt some may hold up their hands in horror at this suggestion, but I would say don't knock it till you have tried it.

 

[MorrisWoodman12]

Thinking back to electronic surface mount component technique classes where the components were literally stuck to the PC and the whole PC assembly put on a hot plate then raised to a temperature where the solder paste (a mixture of granulated solder and flux) melted. Could this technique be worth adapting? You'd glue your ladder rails and rungs to a baseboard in their respective positions, then heat the baseboard and ladder. Either place a chip of solder (I suggest multi core solder with integrated flux) or if you can get it a little solder paste at each joint. Raise the temperature of the baseboard until the solder melts.
Have fun.
Martin