[silentneko]

I am fairly new to working with metal, at least when it comes to welding and such. I've built plenty of stuff using nuts and bolts, but now I'm looking at making a few items out of aluminum.

I'm thinking about making a leaning post, and maybe a poling or casting platform for my boat t be bolted down to the deck.

Since it's such a small one time type project I don't see the point in spending a ton of money on a welding outfit. I was thinking of trying to braze the pieces of tubing together with brazing rods like these:
http://www.harborfreight.com/8-piece-lo ... 44810.html

Thoughts?

[weldin mike 27]

Hey,

welcome to the forum, glad to have you here.

I bought some of those type of things at swap meet a while back.

I havent really had much of a play with them but it seems that you must design your joints for the process. It seems to have zero ductility so the join must have enough surface area to support the forces ivolved. ie: a bent lap joint instead of a t fillet weld. Double sided where possible.

But heres the but. And its abig BUT. Because of the low melting temp of the filler, it is almost impossible to flip a part over and solder the other side because the preceeding solder melts and the part displaces. Maybe it is possible to do as much soldering at one time to avoid this.

It will require some carefull planing as it is not a direct replacement for actual welding processes.

Good luck. Mick

[silentneko]

Thanks for the reply. If I go forward with this plan it will be all round tubing notched into each other, once I figure out how to notch it, lol. So the welds will go all the way around each piece. I know these sticks can be brittle even though strong, they can be tapped and drilled, but does anyone know if they can be polished along with the aluminum?

Would buying a cheap stick welder be a better idea? Or a cheap MIG? I know TIG is expensive and I don't want to have to get gas and all.

[noddybrian]

Hi - silentneko.

I'm in the UK so we don't have the dubious honor of harbor freight ! but I've used a similar looking rod on occasion - in my opinion they do serve a purpose - but it's really non structural repair of small broken parts where the alloy is unknown / not weldable / there is a danger of melting / damaging the part from heating - then these rods work quite well - Mick hit it right on when he mentioned only certain joints suit it & I laughed when he said about re-melting by accident a previous joint as it's very easily done - I've had pretty good results repairing damaged motorcycle casings which are thin & can be almost any alloy known to the Japanese ! the material ( as will any solid metal ) does polish - but virtually no chance of a colour match - so it will always show.

In my limited use of the rods I'd say they really don't suit what you want them for in terms of cost per amount of metal deposited ( despite appearing not expensive - you drip plenty on the floor & get through more than you'd expect ) - strength / reliability of joint - but the biggest issue is they go from solid to extremely fluid in a very narrow temperature band so really only suit joints made in the 1G position - to go round tube joints would require extreme skill / patience & would not be practical.

Please take the above advice as based on my own experience - maybe others have had better / different results & I can't say the rods are identical - but I think it's a fairly generic thing - been around for years - there are a few videos on Utube of this type of rod in use - maybe worth a look.

Last thought - if you are not kitted up for this type of work could you do all the cut / prep then take it to any local shop just to do the welds - ( maybe hang around at lunch break - see if anyone wants a quick cash job ) - if not it's not as neat - but if this thing is all tubular how about using " Kee Klamp" to do the joints - I've seen plenty of it used on fishing boats - also most boat supply shops have a modular / non weld (stainless ) tube system for making handrails - not as nice as bespoke welded jobs - but it works OK.

All the best with your project however you end up tackling it.

[silentneko]

Thanks for the info. Ok so you guys have fairly well talked me out of trying the rods for this type of work.

So how can I get nice clean welds on aluminum without spending a ton? Also which process is easy to learn? Like I said TIG is out because of the cost and skills needed, what about a cheap MIG setup?

[weldin mike 27]

Hey,

Aluminium mig is fraught with dangers, for the under trained or learners. I've never done it, but from what the guys on heresay, and watching jody's videos, there is a lot that can go wrong.You can buy a small mig witha spool gun, but i have no idea of price or capacity.

If you go to a tech school/ welding school or vocational college, you may be able to "borrow" their equpment and space to do the job, and let the students watch / help. When I was at trades school, there was always outside jobs or "foreigners" going on. for people who didnt have the equipment or expertise for the job.

Mick

[noddybrian]

Hi - I think you need to be realistic - until very recently all equipment used for aluminum welding was expensive / specialized & was only in the realm of professionals - even big company shops would have only one setup & usually one guy that had the experience to use it - ( based on UK experience - we don't use that much aluminum - obviously Mick will have differing views as things are a bit different in Aus - they love their ally ) - now you can buy import stuff cheap so people are now using equipment and processes that are not strictly in the hobbyists usual domain - but you still need some welding background / ability / training to make good use of it - bottom line is if you don't have the money available & time to gain sufficient experience admit when your beat & get someone else to do it or change material - aluminum is not really for the novice.

Processes that will weld aluminum.

Oxy / acetylene - I learned with this & it can make a very good weld once mastered - obviously you need the bottles etc - but there are always deals to be had on 2nd hand gear and it's a useful setup for all sorts of stuff.

Tig - nice but you already ruled it out on price / skill & gas supply

Arc / stick - can be done on thicker parts - rods are pricey & always look like Fido's butt ( can be dressed post weld ) requires DC - obviously no gas required - but can get the job done running on cheapo import inverter.

Mig - with teflon / PTFE liner in torch - welds OK - cosmetics depend on wire size / skill / machine - can run on small inexpensive sets - but only in very short bursts due to duty cycle - still needs pure argon.

Mig with conventional spool gun - pretty much the same as Mig still needs argon - uses small spools so relatively cheap to buy - never going to win awards for looks - but gets the job done - I use one for repairing livestock trailers.

New variety of spool gun - not used one - but it's stand alone - only needs a stick weld power supply to run - very cheap - not sure of weld characteristics - must depend a bit on power source - still needs argon.

Cheapest way on smaller job is still have someone else weld it - after that I think change to stainless - then the smallest cheapest inverter can have a valved tig torch added - either scratch start or lift start - you should pick this up fairly fast - there are few variables to sort on stainless - using disposable argon cylinders - probably in stock with the cheap migs at harbour freight or wally world.

[noddybrian]

@ Mick

Good call on the Tech school idea.
Mig welding aluminum is not that bad but does have limitations - if you can setup a regular mig then ally should not cause you any extra problems - available power / duty cycle is always a concern when balanced against wire size available & the ability to feed it - I've used PTFE lined regular torches / spool on & push pull - they all get the job done but I've never fed wire under 1.2mm which is going to need way more volts than than the hobbyist sets manage - if you can track down some 0.8mm wire & get it to feed from a cheap spool gun then you could make a fair job - obviously you have little control of heat input against filler so starts will be cold unless pre-heated & long runs will start to overheat - stop are likely to have minor craters - depends on what you hope to achieve & if looks are that important - most operators with damage to a dump body / bulk carrier / livestock trailer just want it back on the road - never had a sheep complain about the welds on the dividing gates or decks - but then no one told them where their going ! ( insert mint sauce joke ! )

[silentneko]

Well this is all fairly disappointing. I've already looked into schools, they won't let you touch their stuff or bring in a project without being a registered student. Also the shortest class they offered was 30 days and well I'm not going to quit my job so that's out. Having a professional do it was an option, but will run me near a grand for a very small job welding wise but it's a fairly involved job because it has to be done on site and fitted around an engine. It has to be done in aluminum for weight and corrosion resistance.

So basically it's all a bust.

[noddybrian]

Well it was'nt meant to put you a " downer " - but at least we are realistic - I always say don't start something you doubt you can finish.

Now lets try to work round it - aluminum is not noted for strength except in the more expensive fancy / heat treated alloys so you would be surprised just how thin a piece of stainless tubing can be of comparable strength - & it's way better on corrosion resistance - now with a little practice / watch a few video's I think you have a fair chance of some useable welds in this material at the very low end of inverters with disposable gas - so you may be able to do this yourself - do you know anyone has a setup you could try out on to see - if not try another post asking for anyone living close to your area for help.

Still fixated about aluminum - I would assume your not going to weld a structure ( whatever it is ) in close proximity to an engine into one part that's not removable for access to said engine - so how about a slight re-think on the plan so this could be made in a number of sub-structures that bolt together - now you could cut all the parts - trial fit them in situ & once everything is good to go take it in kit form & go round a few shops till you get a fair price - this does away with the obviously expensive option of having a welder on site with Tig gear - still think you would find someone interested in a cash job if it could be brought to a shop - try not to start with a plan & work round every obstacle with a one track mind - step back have another look - there will always be some other way to achieve what you want - get a buddy round - bribe him with beer & pizza ( or whatever it takes ) get someone else to look at what you want to do - maybe the first design you had won't be achievable - but there is always a way to get the job done.

Good luck.

[weldin mike 27]

Hey,

Sorry to bring you down, but least its all out their now. Onwards and up wards now. Good luck . Thanks Brian for the stellar effort put into this post.

Mick

[noddybrian]

@ Mick

Just trying to share my experience - maybe not always right - happy to accept constructive critisism - but I'd like to try and contribute to the forum - I would admit I'd watched quite a few of Jody's video's on and off for some time & never gave a thought to the forum ( not really into using a computer that much & don't write much )- I'd flicked through it as a visitor on occasion - it was just one post about a particular welder I wanted to ask the original poster about so I joined - found it very good so I try to scan it daily when time allows - it maybe I'm wrong - but it seems a whole bunch of people come here for advice & the same few people help them out time after time - sad thing is they just disappear - often without a thank you either never to be heard of again - or only want they want more help - I suppose it's just human nature but it would be nice if there was more participation - I will often post a reply just to try and start the ball rolling - even if my knowledge is not 100% relevant ( I figure I started gas welding age 12 - welded as a job - or welding was a part of my work - now just hitting 50 so I must have learned something useful in that time ) - but often the same questions come up which are easily answered - especially the " I just got a cheap Tig & it does'nt weld like Jody's !"

Can't believe you don't Mig weld ally - thought half you country was made of the stuff - must be quite some industry just in truck bumpers - I think the one on my Toyota pickup came from there.

All the best.

[Otto Nobedder]

Brian,

It's the nature of the beast, on a forum dedicated to a craft or skill, whether it's welding, baking or sewing. Many people join with the hope of getting the answer to a specific question, and once they have it, they never participate again.

That's Okay with me. If only one in fifty will stay and participate, the sooner we attract the fifty, the sooner we have a valuable member like you.

Steve S

[WerkSpace]

If I was on a really strict budget, I would opt for a small portable set of oxy acetylene tanks.
http://www.harborfreight.com/portable-t ... 65818.html

When welding aluminum with gas, it is very important to keep your pressures low (no more than 4 psi)
If you need more heat, go to a bigger tip, but keep those gas pressures low, to prevent puddle blowout.
https://www.youtube.com/watch?v=aF1Srs_e1Aw

Use eye goggles with a gold film lens filter, (it allows you to see thru the orange flame flare.)
Make sure that you use lots of flux paste and practice on scrap materials to achieve your skill level.

When you heat up aluminum, it will not change color like steel does, look for a skin effect.
The base aluminum melts at a lower temperature than the oxide surface layer, thus creating a skin.
When you see the aluminum skin, push your filler rod thru it and start your weld.

[noddybrian]

@ Otto

Well I guess your right & thanks for the comment - but I'd still like to think in a group of like minded people a higher proportion would find the time to give something back - it was a shame when the guy asking for advice on buying a mig or tig had to ask twice before anyone bothered to help him - it only costs a little of our time to hopefully give sound advice but looking through recent posts there are only really 5 or 6 members that are answering all the questions - & two of them are moderators - but I guess you are one of the exceptional guys who are happy to give freely hence your position here .
I'm not any sort of hippy or anything - but if people just tried to help one another where they can instead of just taking - the world would be a better place.

Cheers.

[Otto Nobedder]

It's a sad fact of the internet. A very tiny percentage of those with welding questions land here. Only a very tiny percentage of those will recognize the value of this community.

That keeps us small, and while our growth seems large, the dedicated members who see the value remains small.

This is a good thing, if you've participated in weldingweb and such, where it's almost impossible to contain the snipers, spammers, and trolls.

Let's not fault this forum it's slow pace. It's a blessing others do not enjoy.

Steve S

[silentneko]

I'm down, but not out. I thank you all for your frank responses. When I was a kid there were tons of evening programs around, so you could learn to weld and work a decent job, but these days it seems to have changed. I've found intro to welding classes that just cover the basics of OA and Arc in 30 days, but most of the programs I have found are 6-11 months long. Most of the guys I've known who welded in their garages were self taught, or taught by their fathers. I was not so fortunate.

As far as stainless steel goes, it is an option, but I'm not real fond of it and I can get the aluminum for nearly nothing. In order to get SS that will stand up to saltwater would cost me a fortune.

Now this welding with AO does have me intrigued. How is this different than the brazing? Is it just the temperature? Aluminum melts at 1221F right, so why can't a MAPP gas or propane melt the base metal? Can you produce a similar type of weld to TIG? Stack of coins and all?

Thanks guys.

[WerkSpace]

That stack of dimes look, is going to cost you a lot in practice time. It takes skill and patience.
OA produces a softer more ductile weld and is less prone to cracking.
TIG has a more intense heat zone and thus produces a harder weld and can produce cracking.

With OA, you are truly portable and can take your torches almost anywhere to do the welding job.
If you are new to OA, remember "A before O or up you go".
In other words, light the fuel first and then add the oxygen.

If you are going to weld aluminum, I suggest that you start by focusing on the setup.
I prefer to turn my regulators all the way out/off, then open up the torch valves all the way.
I use the regulators to set the desired flame characteristics and not the torch valves.
This ensures that I will be using the least amount of pressure to weld aluminum with.

I slowly dial in the fuel regulator until I can just feel the fuel coming thru the torch tip.
I light the fuel at the tip of the torch and adjust with the regulator and not the torch valve.
I set the flame to a nice quiet flame, with a minimum of soot.

Next, adjust the oxygen regulator in until you reach the 'Just off the feather' flame pattern.
It is important that you adjust your flame settings so that the flame is quiet.
A loud hissing flame is running at a high pressure and will blow holes in your aluminum welds.
If you need more heat for your welding job, switch to a bigger tip, but keep those pressures low.

Once, you have your regulators properly set up (no more than 4 psi each) you can close the torch valves.
Aluminum welding is fairly easy as long as you understand the process and have some patience.
You will most likely not achieve that stack of dimes look, unless you become highly skilled.
The focus should be on making a solid structural weld. This takes practice.

If you get your aluminum really good and hot, it will weld much easier.
I have both the Meco Midget and the Henrob OA torches but any gas torch will work.
Notice in the following video, how quiet the flame is, try to achieve the same.
http://www.youtube.com/watch?v=FTD6bcFpRVs

[weldin mike 27]

Hey,

Thanks to all,

Brian, on the subject of Alum, The company i work for only makes one thing. The Bushmaster armoured personnel carriers. (you may know them, we sold alot to the U.K) and while the project contains alot of Al mig and tig, we contract it all out because it is not cost effective for us to do in. Boo i say but thats the way of things here.

Best regards Mick

[silentneko]

Thanks Werk Space, that is great info. Can anyone give me a round about cost of what it is to fill those oxy and acetylene tanks? Also how long, at 4psi, will those little tanks last?