grumpy_o_g
Well-Known Member
Are you aware of this thread on the MoBo forum? http://www.ybw.com/forums/showthread.php?t=327844. May be of interest and I'm sure Yoeri would be happy to answer questions.
Welding Aluminium
- Thread starter rustybarge
- Start date
SpottyDog5
Well-Known Member
Welding Aluminium is not difficult, but it is skill you have to spend time to perfect.
I would suggest for your application :
Pulsed MIG with be most suitable process - the pulse of higher power will transfer the droplet, whilst allowing a lower mean heat input.
1.2mm Diameter wire, grade 5356/5183 -thicker wire will overcome the feeding issues.
Push-pull, Spool on gun or a short (3mtr) torch will give the smoothest feed. Amperage range will be anywhere between 150-260 amp, depending on your fillets or butts.
3 phase supply would be best, although this possible on single phase (20amp minimum input) long input leads to be avoided.
Cleanliness of the ali will be everything, oxide removal will help prevent poor welds, you will also need to “tent” up if welding outside.
Your shielding gas with be straight Argon, or you can you some of the argon/helium mixtures.
Tig would NOT be the best process, due to the localised heat input causing distortion problems, it would also be very slow.
BTW- AC for Aluminium Tig, DC for Steel or Stainless steel ,etc.
In my opinion 6mm is too thick for an 8mtr boat, 4mm would be much more workable.
More information, please visit my website.
http://www.rapidwelding.com/dynamic/KnowledgeCentre.aspx?c=MIGWELDINGDOCS
I would suggest for your application :
Pulsed MIG with be most suitable process - the pulse of higher power will transfer the droplet, whilst allowing a lower mean heat input.
1.2mm Diameter wire, grade 5356/5183 -thicker wire will overcome the feeding issues.
Push-pull, Spool on gun or a short (3mtr) torch will give the smoothest feed. Amperage range will be anywhere between 150-260 amp, depending on your fillets or butts.
3 phase supply would be best, although this possible on single phase (20amp minimum input) long input leads to be avoided.
Cleanliness of the ali will be everything, oxide removal will help prevent poor welds, you will also need to “tent” up if welding outside.
Your shielding gas with be straight Argon, or you can you some of the argon/helium mixtures.
Tig would NOT be the best process, due to the localised heat input causing distortion problems, it would also be very slow.
BTW- AC for Aluminium Tig, DC for Steel or Stainless steel ,etc.
In my opinion 6mm is too thick for an 8mtr boat, 4mm would be much more workable.
More information, please visit my website.
http://www.rapidwelding.com/dynamic/KnowledgeCentre.aspx?c=MIGWELDINGDOCS
rustybarge
Well-Known Member
Thanks for all that advise,
Errr.......my heads in a spin!!
Maybe the best idea is to tack weld the boat together...and get an expert to do the welding.
Seems to be some serious problems doing it yourself......bearing in mind when you're bashing & crashing through a head sea at 15 kts wondering if the bloody thing is going hold together.
Or maybe go on a proper welding course.....
Errr.......my heads in a spin!!
Maybe the best idea is to tack weld the boat together...and get an expert to do the welding.
Seems to be some serious problems doing it yourself......bearing in mind when you're bashing & crashing through a head sea at 15 kts wondering if the bloody thing is going hold together.
Or maybe go on a proper welding course.....
garethmking
New Member
Welding aluminium
As an owner of the same 40ft aluminium boat for 30 years the most important issue is the grade and thickness used. It should have approx 4% magnesium to protect against corrosion and this is v difficult to weld. All through hulls should be of plastic such as marelon onto tubing stubs welded to the hull. I suggest you get an experienced builder to build the hull as this is usually only about 30% of the finished boat cost. Go visit a french alu boat builder and see how they do it before you decide to do it yourself. Good luck.
As an owner of the same 40ft aluminium boat for 30 years the most important issue is the grade and thickness used. It should have approx 4% magnesium to protect against corrosion and this is v difficult to weld. All through hulls should be of plastic such as marelon onto tubing stubs welded to the hull. I suggest you get an experienced builder to build the hull as this is usually only about 30% of the finished boat cost. Go visit a french alu boat builder and see how they do it before you decide to do it yourself. Good luck.
SpottyDog5
Well-Known Member
Hello Rustybarge,
I don’t know your location, but I have quite a few customers who make Ali cats, if you need one made, I can put you in touch.
Lots of the kits come in from Australia, ready to weld up, it’s worth a Google.
I don’t know your location, but I have quite a few customers who make Ali cats, if you need one made, I can put you in touch.
Lots of the kits come in from Australia, ready to weld up, it’s worth a Google.
SpottyDog5
Well-Known Member
rustybarge
Well-Known Member
My attitude is either make it all yourself (no need to actually cut down the trees, but buy the planks), otherwise get out the big chequebook.
If you get a boat professionally built, it's just as cheap to buy one ready made. The big cost is labour, and the hull and superstructure are going to cost 90% of the build.
A readymade grp cat would cost less than the total cost of a professionally fabricated alloy cat.
If you get a boat professionally built, it's just as cheap to buy one ready made. The big cost is labour, and the hull and superstructure are going to cost 90% of the build.
A readymade grp cat would cost less than the total cost of a professionally fabricated alloy cat.
SpottyDog5
Well-Known Member
Perhaps you should learn to be a fibreglass laminator then ?
rustybarge
Well-Known Member
Errr, I don't have a temperature controlled shed......problems problems problems.
