Thanks Thanks:  0
Likes Likes:  0
Needs Pictures Needs Pictures:  0
Picture(s) thanks Picture(s) thanks:  0
Page 2 of 2 FirstFirst 12
Results 16 to 30 of 30
  1. #16
    Join Date
    Aug 2009
    Location
    Sydney, NSW, Australia
    Posts
    1,836

    Default

    Maybe Mick can ask a boat shop that welds pressed 3 to 4meter tinnies they are 2-3mm thickness alloy and run full seams

    What is the rate of heat from a normal mig at 70-80amps vs a pulse mig at the same amps?

    Hope u get it sorted mick that is a good looking boat

  2. #17
    Join Date
    Aug 2006
    Location
    Melbourne
    Posts
    1,105

    Default

    Used to do small stitch welds say around 25mm long every 200 - 300mm apart and then they would get scalloped out with a 4" carbide tipped blade to avoid contamination.

    Gazza with aluminium you are nearly running twice the amps you would use compared to mild steel.

  3. #18
    Join Date
    Aug 2009
    Location
    Sydney, NSW, Australia
    Posts
    1,836

    Default

    Com couldnt remember if it were 25amps per 1mm or 40amps per 1mm of thickness

    That carbide cutter is a good idea

    Mick a lot of the big boat builders grind down thete welds so dont be to worried about astetics

  4. #19
    Join Date
    Aug 2006
    Location
    Melbourne
    Posts
    1,105

    Default

    Most of what I was working with was 5mm material so around 200 Amps. Aluminium is like a heat sink so it likes to suck the heat away.

    If you do use those carbide blades, make sure you use a grinder with a deadman (trigger type grinder, not on-off switch) preferable pneumatic. They are very dangerous if not used correctly. Would also recommend full face shield and gloves as swarf goes everywhere.

  5. #20
    Join Date
    Feb 2010
    Location
    Ballina, NSW
    Posts
    900

    Default

    Quote Originally Posted by Com_VC View Post
    Most of what I was working with was 5mm material so around 200 Amps. Aluminium is like a heat sink so it likes to suck the heat away.

    If you do use those carbide blades, make sure you use a grinder with a deadman (trigger type grinder, not on-off switch) preferable pneumatic. They are very dangerous if not used correctly. Would also recommend full face shield and gloves as swarf goes everywhere.
    There was a youtube series of a guy building a boat (I think it was a boat). I couldn't find it again, but I remember that he was using one of these meat axes. I remember thinking it was an accident waiting to happen. Anyway, it got to episode 4 or so, then a delay, then the next one is the guy showing off his bandages. Build on hold. Doctors reckon it'll take a year for him to get some function back into his hand. I've had one of these contraptions, but trashed it - wouldn't have even felt good about selling it to someone. Even a trigger/paddle grinder wouldn't be any good - nobody's reaction time would be good enough. I currently use a carbide burr to feather tacks. I have used a small plunge cut circular saw before - which worked well, but haven't got one at the moment.
    Cheers
    Mick

  6. #21
    Join Date
    Feb 2010
    Location
    Ballina, NSW
    Posts
    900

    Default

    Quote Originally Posted by gazza2009au View Post
    Com couldnt remember if it were 25amps per 1mm or 40amps per 1mm of thickness

    That carbide cutter is a good idea

    Mick a lot of the big boat builders grind down thete welds so dont be to worried about astetics
    The photo is my current boat (when it was new - I just got bare bones and have been adding to it) - but looking to build a bigger one myself.
    Regarding the welding - any reasonable mig or ac tig will weld these planks. Burn through isn't really a problem, even though it is 2mm because it is on the corner of the 2 planks.
    On my current boat I welded an extra plank on the front deck - which required 2m horizontal welds facing down as well as up (i.e. 1G and 4G). The 1G one was easy to MIG (can't remember the settings exactly, but was using 1.2mm wire). However the 4G one it I was having a bad day and ended up tigging it instead. This was 2m of weld lying flat on my back with the weld about 30cm above my face. My tig torch was smoking after that, but credit to my tokentools welder - it didn't miss a beat. I remember running quite hot, I'm guessing it was over 160 amps. Distortion wasn't really an issue as it was inserting a plank into a reasonably rigid structure.
    I definitely won't be grinding these welds down - just wasted time. This will be a work boat, but the welds have to look good and be watertight to satisfy the certifier (for commercial registration).
    Cheers
    Mick

  7. #22
    Join Date
    Aug 2006
    Location
    Melbourne
    Posts
    1,105

    Default

    He obviously wasn't using it properly, you only have a certain area of the blade you can use before they will kick back. I would say most aluminium fabrication places would be using these things. I have spoken to others before and they have used the same thing. A carbide burr would work, but slow going and probably not as cost effective or versatile.


    Quote Originally Posted by WelderMick View Post
    There was a youtube series of a guy building a boat (I think it was a boat). I couldn't find it again, but I remember that he was using one of these meat axes. I remember thinking it was an accident waiting to happen. Anyway, it got to episode 4 or so, then a delay, then the next one is the guy showing off his bandages. Build on hold. Doctors reckon it'll take a year for him to get some function back into his hand. I've had one of these contraptions, but trashed it - wouldn't have even felt good about selling it to someone. Even a trigger/paddle grinder wouldn't be any good - nobody's reaction time would be good enough. I currently use a carbide burr to feather tacks. I have used a small plunge cut circular saw before - which worked well, but haven't got one at the moment.
    Cheers
    Mick

  8. #23
    Join Date
    Aug 2009
    Location
    Sydney, NSW, Australia
    Posts
    1,836

    Default

    Ah Mick so i think i hear u right now your looking for idea's on how to weld the hull without laying under the boat have u thought about making a rotisserie stand? u could do one quiet easily out of steel or wood that way u can stand welding left to right or vise versa, i have never tried to weld over head but i can imagine how hard it must be and tig at that bloody hell awkward much

  9. #24
    Join Date
    Apr 2018
    Location
    Lismore Northern NSW
    Age
    50
    Posts
    81

    Default

    Quote Originally Posted by WelderMick View Post
    There was a youtube series of a guy building a boat (I think it was a boat). I couldn't find it again, but I remember that he was using one of these meat axes. I remember thinking it was an accident waiting to happen. Anyway, it got to episode 4 or so, then a delay, then the next one is the guy showing off his bandages. Build on hold. Doctors reckon it'll take a year for him to get some function back into his hand. I've had one of these contraptions, but trashed it - wouldn't have even felt good about selling it to someone. Even a trigger/paddle grinder wouldn't be any good - nobody's reaction time would be good enough. I currently use a carbide burr to feather tacks. I have used a small plunge cut circular saw before - which worked well, but haven't got one at the moment.
    Cheers
    Mick
    I'll never forget when I saw a guy who had just had one of those blades bounce up into his face... it cut from his jaw up to his eye right through into the bone. You could look into his mouth through the gaping wound and he was hosing blood. I got a pic of him (NFP) but essentially what you'd expect to see if someone hacked you in the head with a sword.

  10. #25
    Join Date
    Aug 2006
    Location
    Melbourne
    Posts
    1,105

    Default

    Quote Originally Posted by Pumpkinate View Post
    I'll never forget when I saw a guy who had just had one of those blades bounce up into his face... it cut from his jaw up to his eye right through into the bone. You could look into his mouth through the gaping wound and he was hosing blood. I got a pic of him (NFP) but essentially what you'd expect to see if someone hacked you in the head with a sword.
    I'm sure this happens quite a lot with chainsaws too...

  11. #26
    Join Date
    Aug 2006
    Location
    Melbourne
    Posts
    1,105

    Default

    Quote Originally Posted by gazza2009au View Post
    Ah Mick so i think i hear u right now your looking for idea's on how to weld the hull without laying under the boat have u thought about making a rotisserie stand? u could do one quiet easily out of steel or wood that way u can stand welding left to right or vise versa, i have never tried to weld over head but i can imagine how hard it must be and tig at that bloody hell awkward much
    Another benefit of Pulse Mig, overhead welds and vertical ups are a walk in the park.

  12. #27
    Join Date
    Feb 2010
    Location
    Ballina, NSW
    Posts
    900

    Default

    Quote Originally Posted by Com_VC View Post
    He obviously wasn't using it properly, you only have a certain area of the blade you can use before they will kick back. I would say most aluminium fabrication places would be using these things. I have spoken to others before and they have used the same thing. A carbide burr would work, but slow going and probably not as cost effective or versatile.
    No definitely not as quick. As with anything, a dangerous tool can be safe in well-practiced hands. As I said, I used to have one - and am certainly aware of how well they work, but in my case I wasn't using it every day and the margin for error was too slim. I recently was at an auction selling off all the tools at a large aluminium fabrication place and that was one tool was notable by its absence.

    Quote Originally Posted by gazza2009au View Post
    Ah Mick so i think i hear u right now your looking for idea's on how to weld the hull without laying under the boat have u thought about making a rotisserie stand? u could do one quiet easily out of steel or wood that way u can stand welding left to right or vise versa, i have never tried to weld over head but i can imagine how hard it must be and tig at that bloody hell awkward much
    Yes a rotisserie would certainly be great particularly with my bad back. It wouldn't have helped in that particular case as the boat already had the motor etc. on so flipping wouldn't have been a great idea.
    With 4G TIG it can be quite therapeutic if comfortable. The trouble with doing a long weld in this position is that it just takes a minute lapse of concentration and - as I did - let the the arc length get a bit long, which resulted in a blob of molten aluminium dropping down. As my face was right under it the blob landed on my mask, but the first I realised something was up was when I started seeing flames rising up through the visor whilst still welding. The blob had dropped at the edge between the visor and the shield and set the plastic underneath alight.

  13. #28
    Join Date
    Feb 2010
    Location
    Ballina, NSW
    Posts
    900

    Default

    Quote Originally Posted by Com_VC View Post
    Another benefit of Pulse Mig, overhead welds and vertical ups are a walk in the park.
    Yes - I hadn't really sussed out how to get the best out of it at that stage - but would happily tackle it that way now

  14. #29
    Join Date
    Feb 2010
    Location
    Ballina, NSW
    Posts
    900

    Default

    Oh yeah... found the video I was talking about. Don't click the link if you don't want to see blood.. https://www.youtube.com/watch?v=_BUTvREU3ZY&t=296s
    Not quite the circumstances that I remember - but not pretty either.

  15. #30
    Join Date
    Sep 2010
    Location
    Lebrina
    Posts
    1,910

    Default

    If there was one thing I could happily see removed from the face of the earth, it would be carbide cutters for grinders.
    I don't know how they are still in widespread use as they turn a grinder into a circular saw, which by law must have a spring loaded guard, which of course, grinders do not. Way more dangerous than a chainsaw as a chainsaw has a both a chain brake and a much better handle system than any grinder.

Page 2 of 2 FirstFirst 12

Similar Threads

  1. Small aluminium boat trailer build
    By gazza2009au in forum TRAILERS & OTHER FABRICATED STUFF
    Replies: 9
    Last Post: 22nd Dec 2017, 12:43 PM
  2. Boat building for fun & profit
    By PDW in forum METALWORK PROJECTS
    Replies: 9
    Last Post: 13th Dec 2015, 01:44 PM
  3. Building a Aluminium I Beam Trailer
    By gazza2009au in forum TRAILERS & OTHER FABRICATED STUFF
    Replies: 58
    Last Post: 30th Mar 2015, 11:45 PM
  4. Replies: 44
    Last Post: 24th Aug 2014, 07:51 PM
  5. Protecting new unpainted aluminium boat
    By seanlark in forum METALWORK GENERAL
    Replies: 27
    Last Post: 21st Sep 2013, 03:55 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •