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Discussion Starter #1
Hey all,

I have a Mirage 27 from 1980 and its mast is down for the first time since 2003. I've done a fair bit of inspecting and all seems well apart from the curious nature of the spreader connections. Please see the attached photos. This does not look good to me.

I can't really explain away how this happened. There is no bending on the spreader itself nor the mast behind it. How is it possible that this stainless piece of hardware bent out like this? The port side is worse than the stbd. This asymmetry tells me that this isn't normal.

The spreaders should be in compression, no? If they were "wobbling" to cause this damage wouldn't the spreaders be bent since they're much weaker than the stainless? One would expect some damage to the surface of the mast as well, no?

Can I just bring this to a machine shop to flatten the edge? Mirage no longer exits so I can't imagine I'll find replacement parts for this.

Any thoughts or advice regarding this would be greatly appreciated.

Thanks for listening!
Trevor
 

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The spreaders have a lot of leverage.. someone attempting to force the spreaders up to the optimum angle may have induced that effect if the spreader cups were not designed for it.

Puzzling, but there it is. Any sign of stress cracks where the cups join the plates?
 

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That happens to that type of spreader base. The plates will bend before the aluminum spreaders tubing will. the plate is very soft SS and can bend easily if the spreader is stood on while climbing the mast or the spreader is hit while the mast is down. take the brackets off the mast and straighten the plates by holding in a vice and tapping with a hammer. they will bend back easier then you think. inspect for cracks and they can be re welded if cracked.
 

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Discussion Starter #4
That's an easier solution than I was thinking. The welds all look quite good, so I don't think I'm in danger of catastrophic failure or anything like that. I'll take them off and bring them to a keen machinist to put them back in their proper form. That should put my mind at ease. Those bolts don't look happy due to the deformation.

Just to be clear, they're supposed to be flat, yes? No curvature? The angle of the lower shrouds I can calculate easy enough based on the rigging dimensions and the machinist can replicate that if need be.
 

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yes the would be flat and the angle is built into the bracket, tube is welded on at a slight angle to the flat ss plate. be careful when you remove the brackets as there may be a spacer tube inside the mast to keep from crushing the mast with the bolts. use a piece of round stock or piece of wire to push the original bolts out so you don't loose the spacer tube inside the mast. some masts have them and others don't
 

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mine bent in a similar fashion, it was from an improper tension on side stay and mast was putting tension on each side under load. a loos guage and 30 mins of re tuning the rig sorted it. a small wooden dowel placed into slot and a easy but steady whack with mallet will set spreader reciever back into place. do not heat it up as it will weaken on you, (ask me how i know ). then when mast is back inplace re tension using the loos guage and your golden.
 

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I don't have much to offer Trevor except that if it were me I would heed overbored's advice regarding the possible spacers, if they fall inside the mast you will have a real problem. If you remove the bolt follow it with something to keep the spacer in place. If there is no spacers it doesn't matter but I would assume there is.
 

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Discussion Starter #8
Hey all,

So I finally got these off and straightened out. There is a spacer in the centre of the whole kit with a large bolt through. There aren't spacers on the four bolts surrounding it, which I find odd. I'm guessing they existed at one point and a previous owner didn't do as you all have been suggesting and lost them.

I think this may actually have caused the problem in the first place - allowing the upper and lower portions to flex and compress the mast while bending the pieces themselves. Once I straightened out the pieces I actually had to grind the centre spacer a little bit. Seems like the outter bolts were about 5 mils too short. Anyway, its all together and tightened again. I tired not to over-tighten the outter bolts much as to not causing too much compression, but I'm guessing that in 10 years or so I'll have to do all this again.

I don't like this continual compression of the mast over time, but seems as if there are some configurations like this that don't have the spacers, so here's hoping I'll be fine.

Any thoughts either of you would like to add? Should I try to fix this up a bit better? Loosing the mast due to something like this would not be a fun day.
 

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Discussion Starter #9
So I've just thought of a way I could add the collars. Please see the attached diagram.

I would drill the 4 outer bolt holes on the mast larger only on one side (the mast is laying on its side right now). I could then put the bolt through the non-widened side, then slide the collar down over from the widened side, put on the spreader mount, and tighten.

This way I don't loose the collars, I can be reasonably accurate with the length of the collars, and I still "pinch" the mast a little, albiet only on one side.

I've attached a closer view as well. Note the collar is orange and the bolt is red.

Thoughts? Am I overthinking or would all this be just peachy without the collars?
 

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I think your idea is sound Trevor but make sure the collars are the correct length so that the bolts tighten without squeezing the mast.
However, I would guess there were no collars on the outer bolts. I think the centre collar takes the compression load while the outer bolts keep everything aligned.
I don't think there is any lateral load on the spreaders, unless people are jumping up and down on them and you shouldn't have any need to do that.
 
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