Crack in mazt
- Thread starter Gina Hopen
- Start date
yes it can you may have to take it down so the welder can do the job but it beats the heck out of buying a new mast just make sure you find a good welder that has experience in welding aluminum with heli arc
You can weld aluminum masts as Woody suggests but Dave's concerns are justified.
Aluminum masts are subject to high loads and designed to flex. A crack really compromises its ability to do both jobs. Any possible repair has to make sure that:
The crack does not spread
The reason it cracked is eliminated
Any sleeving or patching does not effect the masts ability to flex, or create a large 'hard point'.
Hard points focus bending stress at the edges of the hard point; this creates another potential failure area.
This is complex and serious business. Its not just an issue for a welder. Have someone competent look into it; someone without a vested interest in either selling you a new stick or firing up their welder.
Aluminum masts are subject to high loads and designed to flex. A crack really compromises its ability to do both jobs. Any possible repair has to make sure that:
The crack does not spread
The reason it cracked is eliminated
Any sleeving or patching does not effect the masts ability to flex, or create a large 'hard point'.
Hard points focus bending stress at the edges of the hard point; this creates another potential failure area.
This is complex and serious business. Its not just an issue for a welder. Have someone competent look into it; someone without a vested interest in either selling you a new stick or firing up their welder.
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at the risk of starting a pi$$ing contest here just make sure you find a good welder that has experience in welding aluminum with heli arc this means don't get joe blows back yard welder to do the work i have done a lot of welding in my day as in certifying in nuclear welding and worked that craft for more years than i care to count this day and time ...this was not a frivolous recommendation....and as jack stated make sure you find the source of the crack and also make sure you stop the progression ....we have no idea what or exactly where the crack is it could be in a mast fitting or on the mast itself..... if in either case a good welder will know his limitations and weather it is repairable or not so don't count welding out ...a good welder will be knowledgeable in the astm requirements ...and as you say dave it could be a critical area so proceed with caution
Guys, I'm sort of agreeing with both of you.
I have seem many successful mast repairs. The TRICK is that the mast (unlike most metal items) is designed to flex. This changes the dynamic of the repair completely and has to be accounted for by someone that understands this at a deep (engineering) level, and not just a welder who can make a workmanlike repair. No disrespect intended there; those are just two different jobs.
In my experience, repairs are very possible, straightforward, and successful at the ends of the mast. As you move to the middle, it gets more complex. But not necessarily impossible. Its important to note that many long masts are shipped in TWO pieces and sleeved together at the commissioning point! The key is it is a highly engineered solution.
I have seem many successful mast repairs. The TRICK is that the mast (unlike most metal items) is designed to flex. This changes the dynamic of the repair completely and has to be accounted for by someone that understands this at a deep (engineering) level, and not just a welder who can make a workmanlike repair. No disrespect intended there; those are just two different jobs.
In my experience, repairs are very possible, straightforward, and successful at the ends of the mast. As you move to the middle, it gets more complex. But not necessarily impossible. Its important to note that many long masts are shipped in TWO pieces and sleeved together at the commissioning point! The key is it is a highly engineered solution.
i am sitting here wondering how many airplanes are going to fall out of the sky because they were tig welded by a competent welder totally amazing .....there is a big differance in a crack weld repair and a total butt weld when it comes to a mast or anything else for that matter and we still don't know what the crack looks like on that mast in question so speculation is out the window here as they say.... its their boat there choice .....and yes i understand as a former dealer on your part you have a liability habit to maintain and uphold....also i mean no disrespect to you or your knowledge and experience but you don't know what i know when it comes to welding ...i can weld your initials on the bottom of a PBR can (.019 thick) tig welding without blowing a hole it the metal just for example.... ...there is an art and a science to welding that was developed by the AWS and the US Navy ....and it is possible that if after inspecting the crack that i would elect to not weld it but only after my inspection ...my recommendation to weld it is not cast in stone
OK.. my turn to beat the horse before it dies!
Let me say that I have never encountered anything (metal) that couldn't be welded.. (I was lucky that I had access to a world wide gang of metallurgists, welding engineers, and testing engineers and technicians).. That said, sometimes the preparation and mitigation process for welding success exceeded the cost of a new part.. but the primary decision to weld or not to was always made on the premise that we knew the root cause of the crack, and we knew how we were going to inspect the weld to insure that the weld itself would not cause a failure. Sounds like we all have no info on the real cause of the crack, so until that can be known, I would not lobby for or against welding. I would not condemn all welding on a spar, but I would not weld on one until I thoroughly understood what had caused the crack.
I will step down from my soapbox now.
Let me say that I have never encountered anything (metal) that couldn't be welded.. (I was lucky that I had access to a world wide gang of metallurgists, welding engineers, and testing engineers and technicians).. That said, sometimes the preparation and mitigation process for welding success exceeded the cost of a new part.. but the primary decision to weld or not to was always made on the premise that we knew the root cause of the crack, and we knew how we were going to inspect the weld to insure that the weld itself would not cause a failure. Sounds like we all have no info on the real cause of the crack, so until that can be known, I would not lobby for or against welding. I would not condemn all welding on a spar, but I would not weld on one until I thoroughly understood what had caused the crack.
I will step down from my soapbox now.
As an aircraft builder and a TIG welder I'd say that, yes, a mast can be welded. Creating a hard-spot due to welding should not be too much of an issue, as the TIG welding process does not usually heat the surrounding aluminum for long enough a time to change it's qualities. Also, the area actually heated is so small to begin with that it really doesn't matter. The usual standard for welded T6 aluminum is to accept it in 'as-welded' condition.
Additionally, we are only talking about the side of the mast at the spreader. I might be concerned if we were talking about the fore side of the mast where we are dealing with tensile forces. The tensile strength of filler rod can vary around, say 37-39000 lbs and T6-aluminum (yield strength) is about 35000...but the filler strength can vary for a variety of reasons. But remember that 35000 for aluminum is the point at which it starts to deform, not bend, so I would be comfortable with the filler coming in at the low end, even slightly below the yield strength of the base aluminum mast. At 35000 lbs the whole mast might come down anyways.
In welding I would worry more about breaking strength than the bending forces initially. A good weld just isn't going to break. Usually the metal will go before the filler...in a good weld. A good weld is no different than, say, drilling a hole in the mast and then putting in a tight bolt. The aluminum filler rod will generate less of a 'hard spot' than a stainless steel bolt. Another thing too, we're not talking about a complete circumferential weld...but that's what sleeving a mast together is for... If a big sleeve doesn't cause a problem a TIG weld won't either.
Last..you shouldn't have to bring the mast in...but the welder might need a wooden ladder to stand on so as not to complete the circuit between the 'torch' and the mast. The voltage of TIG can be dangerous if not careful.
Thanks for all of the input. I am taking her to a marine welder and having an appraisal done. I'll let you know how it goes. I just want to get back on the water!
I think you made the correct choice. Funny how some are totally against welding a crack but are first in line to cut a slot in the mast and add an in-mast halyard exit...
Time will only tell. Hope to get a report back later in the summer after the good sailing season is over