soldering brass rods

max142 · Post by **max142** » Sat Oct 01, 2005 4:43 am

Hello Reader,

Can I get some advice on soldering brass rods. I want to make a connecting structure to bridge an engine pod and main hull. I figure the stucture to be 9" in length and non load bearing (parts will actually be supported by the stand).

I have soldered electirical componets and have a small soldering iron. but I could use some advice.

Thanx in advance,
Max

en'til Zog · Post by **en'til Zog** » Sat Oct 01, 2005 11:16 pm

Heat. Solders in different 'harnesses'. Patience. A good jig for holding the pieces. Practice.

Heat - a pinpoint torch will probably be a necessity. Lots of heat in a tiny area, quickly. Why quickly? So the heat won't have time to travel to different parts of the structure and UN-solder them.

Solders in diffrent 'hardneses' - If you start the major bits of the frame use the 'Hardest' solder - that's the solder that melts at the highest temperature. Then attach the minor bits with 'softer' solders that melt at a lower temperature so you don't un-solder what you've already done.

A good jig - 'cause you will probably over heat some adjacent joints from time to time and it's nice to not have the entire thing SAG when you're nearly done.

From the little brass frameworking I've done, successful soldering has a lot to do with planning what bits to add when.

Now - doew anyone who's scratch built an EAGLE framework have a lot MORE detailed inflamation?

b5ranger99 · Post by **b5ranger99** » Sun Oct 02, 2005 9:12 pm

Only thing I would add is heat sinks , between the joint you are soldering and the joints you have already soldered.

That and plan the work so you can move from one end or area to another so the work will cool, eg needs more time to reach melting point.

Ok thats two points, heat sinks and plan the work.

And plan the jig (possibly rotate) and work so you can work from the top down because heat rises, although the biggest problem will be conduction.

OK thats three points heat sinks, planning and work from the top down.

And a tip I picked up from a model railroading magazine, wet sand can be packed around nearby joints or heat affected items eg plastic to protect from heat.

OK thats 4, oh buggers I'll go out and try it again.

max142 · Post by **max142** » Wed Oct 05, 2005 3:37 am

thanx for advice.
guess i'll start a jig and get a higher wattage iron...my current one is 45watts.

Shinnentai · Post by **Shinnentai** » Thu Oct 06, 2005 11:02 pm

For structural stuff like this, a butane hand torch is much better than a soldering iron (way cheaper too). An iron is too specific in it's coverage, and will make it much trickier to heat the joint evenly. A gas torch also gives you better protection against oxidation/scaling.

max142 · Post by **max142** » Fri Oct 07, 2005 3:55 am

thank you again. I'll stop by Home Depot this weekend to pick up a torch.

Just found out my grandfather is visiting from CA. No modelling this weekend.But, that is a good reason .

shrugger · Post by **shrugger** » Fri Oct 07, 2005 11:52 pm

Self learned and did all myself.
http://public.fotki.com/shrugger/eagle_11/
In one of the pix you can see the torch I'm using. I think it was
$6 at Lowe's and works great.
Unless what your building is huge and you need all the structural
strength you can get, then brass tube would be alot easier to work
with than brass rod as it won't sink near as much heat away from the joint.
It can be gotten in a wide varity of wall thickness' depending on how
strong you need it.
I've tried pretty much all the fluxes and solders. Don't use the water
soluable flux as it just seems to burn.
The one that I found works best for me is the paste solder. Its already
mixed with flux and comes in a plastic syringe. Your taste however may differ from mine.
Also don't apply heat directly to the solder, but heat the area all around it.
It's a beautifull thing when the brass reaches temp and the solder just
flows where you take the heat.

Also, Something I learned from DX-SFX
Because solder will follow the heat, it can occasionally go where you don't
want it to. If you take a graphite pencil and draw a line around your area
it will stop it from travling any farther.

And one other thing *CLEAN* keep the brass as clean and freashly sanded
or steel wooled as humanly possible. Solder does, in no way, like oxidation. Don't ask me why. They just don't like each other

Jades Dark Heart · Post by **Jades Dark Heart** » Sat Oct 08, 2005 1:09 pm

Hey shrugger long time bro. That is really nice work. What are you using to cut the brass there?

Greg

shrugger · Post by **shrugger** » Sat Oct 08, 2005 6:20 pm

AAh.. heres the pic
http://www.harborfreight.com/cpi/ctaf/D ... mber=42307
Got this little cut-off saw at Harbor Freight regular price $19 but it was
actually on sale for $16

They getcha though with replacement
blades, 3pack for $10. I'm on my 7th, and hopefully last blade.
Thats a whole lot of brass to cut after all!!
The "Swearing Factor" alone has paid for this thing several thousand times
over

shrugger · Post by **shrugger** » Sat Oct 08, 2005 6:25 pm

oops looks like they raised the price

Jades Dark Heart · Post by **Jades Dark Heart** » Sun Oct 09, 2005 9:23 pm

still a good price for a very usable piece of machinery

Lo pan · Post by **Lo pan** » Wed Oct 12, 2005 10:43 am

I have a kit with turned brass parts (gun barrels) that must be mounted on another part (turret) that is a different metal. The larger part is cast metal, but far harder than any white metal I've ever seen. Do any of you guys have experience soldering somthing like this? Will the torch and solder work?

Here's a <a href="http://www.future411.com/cinemafictions ... pg">pic</a> of the turrets in question.

Thanks.

shrugger · Post by **shrugger** » Wed Oct 12, 2005 11:02 am

If those pieces are white metal, and they look like they are. Then
solder wouldn't do at all. The melting points of the two are very close together.
And I don't think they like each other very much anyway.
Your best bet would be to drill holes into the piece and into the end of the
barrel's then pin (Paper clips are great for this) them together using epoxy
or super glue.
Hope that makes sense.

Lo pan · Post by **Lo pan** » Thu Oct 13, 2005 12:14 pm

Shrugger,

That makes sense, but I don't think they they're the run of the mill white metal parts. Maybe pewter or some other sort.

How's this for a qualitative analysis: They "clink" in the bag together, they don't "clonk" like other white metal pieces, they are relatively light, they hold their shine, shrug off direct and sustained contact with a soldering iron, and laugh at grinding bits. I'm tempted to say they're steel, but why would somebody use that for a kit part?

The parts are from a 1/350 Andromeda from Space Battleship Yamato/Star Blazers. Anybody else seen this puppy?

shrugger · Post by **shrugger** » Thu Oct 13, 2005 12:38 pm

Well now, thats.. differant

I think steel can be soldered, but it needs to be 'Clean Steel'.
By that I mean impurities clean, not in the sink clean. lol
If your feeling lucky give it a try. I still think epoxy would be the best way
to go though.

Shinnentai · Post by **Shinnentai** » Thu Oct 13, 2005 3:49 pm

I'd use JB Weld for that. Less of a hassle than working out how to solder it, and the bond will be just as good (better than ordinary epoxy when dealing with metal parts).

Just make sure it's the regular JB Weld. That "JB Quick" stuff is crap.

Lo pan · Post by **Lo pan** » Fri Oct 14, 2005 12:08 pm

Thanks for all the suggestions guys. I'll give the JB a shot.

shrugger · Post by **shrugger** » Fri Oct 14, 2005 1:02 pm

I think he may be right about JB

m_ubelaker · Post by **m_ubelaker** » Fri Oct 14, 2005 11:54 pm

The one thing I can say is CLEAN the brass. I use a wire wheel in my Dremel to clean it. You want the brass to sparkle before you start solder. Then be sure to heat it red hot cool it then solder the two peices together.

Just my way.

shrugger · Post by **shrugger** » Sat Oct 15, 2005 1:50 am

Don't know about the pre heating thing. My little butane can't 'cherry'
brass anyway, and it's fine. But clean is a must. I've gotten in too much
of a hurry now and then and usually ended up paying for not cleaning
it like I should have

Shinnentai · Post by **Shinnentai** » Sat Oct 15, 2005 1:18 pm

shrugger wrote:My little butane can't 'cherry'
brass anyway,

Hmm, it should be able to pretty easaly. I've annealed steel and melted glass with mine. How are you adjusting the flame? What part of the flame are you using?

DX-SFX · Post by **DX-SFX** » Sat Oct 15, 2005 7:02 pm

The one thing I can say is CLEAN the brass. I use a wire wheel in my Dremel to clean it. You want the brass to sparkle before you start solder. Then be sure to heat it red hot cool it then solder the two peices together.

Er...No. Sorry, this is not a good idea. Getting brass that hot not only anneals it, it encourages the surface to oxidise. Same with steel. Just make sure the two are reasonably clean, use an additional flux like the white paste type plumbers use and make sure both parts are above the temperature at which the solder melts (tin/lead solder roughly 180 degrees c). If the joint is hot enough, the solder will flash through the joint. If the solder "balls" up, the parts aren't hot enough. You might want to consider tinning both parts first, particularly the steel and then just playing some heat on them while holding them together.

Cast metal parts aren't a good thing to learn soldering on. The melting point of cast parts is nearly always low (which is why these metals are used) and there's an inherent danger of not only melting the solder but the part as well. White metal kits melt at the same temperature as conventional "soft" solder. It's possible to buy a very low temperature solder specifically for white metal but it's not ideal for steel or brass.

The only time brass or steel need to get near to red heat is if you're using silver solder or other brazing alloys and you need a completely different flux to deal with the oxidation at those high temperatures.

Shinnentai · Post by **Shinnentai** » Sat Oct 15, 2005 9:05 pm

What he said.

When I said I'd used the torch to anneal steel, I didn't mean for soldering. I was annealing 2/10" steel piano wire so I could coil it to make chain mail links for a costuming project. Heat oxidized the crap out of it, but that was OK because it gave the finished mail a nice dark aged look.

Also, for torch soldering, it's good to have an insulating/heat reflecting surface to work on. A chunk of firebrick or even the underside of a ceramic tile is good. I think someone already mentioned the sticking the finished bit in dry sand to let it cool bit (very very important the sand be dry).

shrugger · Post by **shrugger** » Sun Oct 16, 2005 12:42 am

Waay too much trouble. Heat, melt, cool, done.

Shinnentai · Post by **Shinnentai** » Sun Oct 16, 2005 12:57 am

Guess that depends on how durable you want it to be.

shrugger · Post by **shrugger** » Sun Oct 16, 2005 1:40 am

Nah, it's plenty durable to air cool. Just don't stick your piece in water
to cool it faster. Both the brass and the solder could 'shock cool' causing
them to crack. It's not as much a problem when soldering as with Brazing
since youre working at a lower temp, but it could happen.

Shinnentai · Post by **Shinnentai** » Sun Oct 16, 2005 3:31 am

Ah, my misunderstanding. Yeah, the sand thing is overkill for most ordinary work (more of a glass thing anyhoo).

Got me as to why I even brought it up. Brain fart, I guess.

en'til Zog · Post by **en'til Zog** » Wed Nov 30, 2005 6:27 pm

(bump)

big-dog · Post by **big-dog** » Wed Nov 30, 2005 11:22 pm

Keep checking Harbor Freight, I got that exact same cutoff saw for 16 bucks a coupla months ago on sale too. And the regular price was 30 bucks. They have some great sales. Then again there's a store about 20 minutes down the road. So far from them I got a mini table saw (4" blade), 12" table scroll saw, micro lathe thingy (knock-off of a unimat, even compatible-same rating on the motor), the cutoff saw, a sander, and today a 1/3 horsepower benchtop drill press, 5 speeds, 1/2" chuck, sale price plus coupon came to the princely sum of 32 bucks. The table saw was the most expensive thing at summink like 50 bucks, but then it's all metal, weighs a ton, has mitre grooves both sides of the blade etc.