Hi all. I'm looking to get some opinions. I purchased the boat with some hurricane demage. Below are pictures of the spreader that broke off and ripped the part of the mast with it. I was hoping I can hear some opinions if this is safe to weld or should I get a new mast. Thank you.
Fix or replace mast question
- Thread starter sasafil
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- hunter 35.5 legend
Are all the pictures of the same spreader? Assuming yes, I would look at removing the spreader bracket, flattening the mast section to fit back into the place where it is, weld in (full penetration weld) ground smooth and then weld the bracket back on. As an added level of comfort you could add a reinforcement plate over the mast repair and then weld the bracket onto the new reinforcement plate.
You are correct DayDreamer41. It is a same spreader. I was told by a rigger that the repair would not be safe. That spreader could broke off in a heavy weather. That is why I'm looking for other opinions.
I agree with Daydreamer and Brian that you could repair the damage area by adding a patch that would cover both sides (25% extra coverage). This would make the area stronger than original, the main concern would be the welder as not many know how to weld aluminum with out affecting the strength of the original material.
There are a series of aluminum alloys that may have been used in the original mast. I would have a small piece analyzed to know what specific alloy the original mast was made from. with that information I could then give a better opinion as to re-welding or putting up a new mast.
dj
dj
If insurance covers the damage, then get a new mast and let them pay for it. If you are on a budget, I agree, a good aluminum welder can fix it.
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 22,758
Dave. Has a point about the material used. Is it a Selden mast? I’d call the mast manufacturer and explore the solution> They may be able to provide more information. The original looks like a pile on weld. I have seen cleaner jobs. The force to rip that base had to be severe. Once the spreader base is removed you will want to inspect the mast for further cracking or weak spots. Once clened up (Perhaps install a plate over the damaged area) it may be possible to weld a new base (or the old base after the old weld is removed) and be good. Other repair plans would be to cut the mast and install a sleeve over or inside the damaged section. Then inserting the upper mast section into the top of the sleeve. The mast should be stronger then before the failure.
I can tell you the failure of that piece was mostly due too severe undercut, you can see it on the cracks and you can see it on the actual break,any good welder would cringe at that!
I just realized you are not just welding the mast back together, but you are welding the aluminum base of the spreader arm to the mast.
That being the case, you really should know what both the alloy of the mast is, and the alloy of the spreader base is. The spreader base looks like one of the cast aluminum alloys.
Looking at your photos more carefully I'm realizing what you currently have is a cast aluminum spreader base welded with an unknown filler material onto an unknown base aluminum mast. Are you trying to reuse the spreader base? If you are, I'd recommend you remove the original weld bead material. That's going to take a bit of work.
You will end up with two separate welds, the welding of the mast side back together and then the welding of the cast aluminum spreader onto the mast.
Honestly, I think your better option is to cut this section of the mast out, sleeve it as suggested by @jssailem then weld the spreader base back on. You still should determine what the aluminum alloys are, it will really help choose the correct filler material.
dj
That being the case, you really should know what both the alloy of the mast is, and the alloy of the spreader base is. The spreader base looks like one of the cast aluminum alloys.
Looking at your photos more carefully I'm realizing what you currently have is a cast aluminum spreader base welded with an unknown filler material onto an unknown base aluminum mast. Are you trying to reuse the spreader base? If you are, I'd recommend you remove the original weld bead material. That's going to take a bit of work.
You will end up with two separate welds, the welding of the mast side back together and then the welding of the cast aluminum spreader onto the mast.
Honestly, I think your better option is to cut this section of the mast out, sleeve it as suggested by @jssailem then weld the spreader base back on. You still should determine what the aluminum alloys are, it will really help choose the correct filler material.
dj
Totally agree. (I also totally agree with you that that original weld looked like about two steps below dog $hit... maybe those weren't exactly your words..
)That's why I recommended to remove the original filler metal. In fact, if I had access to a machine shop, I might put that base on a mill and just cut off all previous weld bead while at the same time making a good preparation surface for the subsequent welding step.
dj
I have to admit, I've never seen a spreader base welded to a mast before. Welding aluminum can be very strong with the right materials but if you weld to heat treated aluminum you may greatly reduce the strength and end up with a failure that looks just like what you see in those pictures.
Even "weldable" aluminum, such as many 5000 series, can have a reduced yield strength when welded. For instance 5083-H32 it will go from about 34 ksi to 18 ksi yield strength. If you are looking at 6000 series aluminum, it is really dependent on the heat treatment. 6061-T4 has a yield strength of 16 ksi, about the same as the Heat Affected Zone after welding but 6061-T6 has a yield strength of 35 ksi, which drops to 16 ksi in the Heat Affected Zone after welding.
So you REALLY need to know what material you have before welding aluminum, not just to ensure the proper filler, but also to understand what will happen to the strength of the substrate.
Welding is not necessarily stronger than other forms of attachment, and is some times much weaker.
BTW, the mast extrusion is likely a 6000 series aluminum but only the manufacturer could tell you what heat treatment was used.
Even "weldable" aluminum, such as many 5000 series, can have a reduced yield strength when welded. For instance 5083-H32 it will go from about 34 ksi to 18 ksi yield strength. If you are looking at 6000 series aluminum, it is really dependent on the heat treatment. 6061-T4 has a yield strength of 16 ksi, about the same as the Heat Affected Zone after welding but 6061-T6 has a yield strength of 35 ksi, which drops to 16 ksi in the Heat Affected Zone after welding.
So you REALLY need to know what material you have before welding aluminum, not just to ensure the proper filler, but also to understand what will happen to the strength of the substrate.
Welding is not necessarily stronger than other forms of attachment, and is some times much weaker.
BTW, the mast extrusion is likely a 6000 series aluminum but only the manufacturer could tell you what heat treatment was used.
As I understand it, the majority of masts are made from 6060-T6, 6063-T6, 6061-T6, 6082-T6, or 7075-T6. I'm not aware of other tempers being used, but I guess they could be. If the mast is made outside the US then other tempers might be more possible. This is not some high-performance specialty mast. If that were the case, then all bets are off.... (Plus, then it's be made from carbon fiber, not aluminum...)
If it is a US manufactured mast it is likely 6061-T6 as that is a very good aluminum alloy to use and readily available in the US market. I guess they could use a T4 heat treatment for this alloy, but I don't see why they would. 6061-T6 is so readily available and a stronger heat treatment.
The real question is the base chemistry of the mast and the cast spreader arm base. Knowing that, you can then select the filler rod you need to get the best balance of strength, ductility and corrosion resistance.
That's just my 2 cents worth...
dj
(Plus, then it's be made from carbon fiber, not aluminum...)If it is a US manufactured mast it is likely 6061-T6 as that is a very good aluminum alloy to use and readily available in the US market. I guess they could use a T4 heat treatment for this alloy, but I don't see why they would. 6061-T6 is so readily available and a stronger heat treatment.
The real question is the base chemistry of the mast and the cast spreader arm base. Knowing that, you can then select the filler rod you need to get the best balance of strength, ductility and corrosion resistance.
That's just my 2 cents worth...
dj
Sasafil,
I'm assuming you got the boat for a discount with that ASSUMPTION you'd have to replace the mast. Now is that time to realize that assumption was correct.
For reasons cited above about the changed strength and continuity of materials, I'd never trust a patch like that. IF the cast was "broken" cleanly in a different location, then MAYBE. The problems are not just restricted to the side of the extrusion; and, I really think the welds and loading of the spreaders had to be designed for more than a little moment (i.e., bending) loading.
I'd certainly reinforce the thoughts of calling the manufacturer and sending them the complete story. I'd be amazed if they didn't tell you the same thing.
How much is a mast with the spreaders? Maybe you salvage the fittings, etc. -- maybe not.?
@dLj is probably right, most masts are very likely 6061-T6 which is why you just don't see fittings welded to masts. The yield strength is reduced to 1/2 of the original when you weld 6061-T6 aluminum unless you post-heat treat. Just don't weld it.
If you ever want to fully trust the rig, listen to @SG - get a new mast extrusion. Or find one from a similar boat that is being parted out. And don't weld the spreader fittings on!
If you ever want to fully trust the rig, listen to @SG - get a new mast extrusion. Or find one from a similar boat that is being parted out. And don't weld the spreader fittings on!
Check with sailboatwreckingyard.com. They have parted out over 450 boats and have numerous masts on site.