Isomat mast

[catalina1]

I have a Isomat mast fitted on a 28ft boat.
The rigger informs me the spreaders are not the correct ones..
He says
"The spreaders do not appear to be the correct ones for the mast so there
is excessive play between the spreader roots and the spreaders"
Where would I buy or have made a set of spreaders ?
Are Isomat still in business? the boat is 1981

 

[merlin3688]

Isomat are now Sparcraft, speak with Adrian at Eurospars, they are a Sparcraft agent and will be able to help you.
http://www.eurospars.com/

 

[merlin3688]

The spreader section should look like a tadpole, 3 sizes were available and I think BF3 was a part number, they also had a nylon bush on the pin to take away the slop, maybe this is missing?

 

[catalina1]

Thank you Merlin 3688.
That sounds a fair point
I shall ask questions at eurospars.
If this is the case, is it possible to remove spreaders in situ.
The boat is on the river mid steam pontoon , and make mast safe whilst taking spreaders away for work ?

 

[merlin3688]

It would be odd to have the wrong spreader section fitted, Isomat used to weld the spreader bracket on and the spreader profile should be correct, from memory they were never a great fit, it may be possible to pack the lug out to make the spreader a better fit. Yes to your question, just put a halyard out each side and the mast will be ok.

 

[catalina1]

Once again
Thank you

 

[merlin3688]

This is the spreader section you should have.
http://www.rigrite.com/Spars/Isomat_Spars/Isomat_Spreaders/BF3_spreader.php

 

[catalina1]

Yes
I have looked at those drawings
I think rigger has got is a twist over a poor fit
i think I shall have him take off spreaders, inspect, order as we see fit ( or make) and refit

 

[Slowtack]

My fractional keel stepped Isomat has roots welded to the mast as described above so I take care when lifting the rig as I have heard these are regarded by surveyors as non-repairable if aged. There is a little play but not excessive when the mast is down. There is a plastic insert in the root hole where the pin goes through. Some wear there might increase the movement but once the mast is in position and upper halyard is tight there should be no movement and the spreader should be in compression. I take the spreaders off when ashore for the winter to avoid wind shake damaging the spreader system. I have found Rig-Rite very helpful and they have a large stock of parts.

 

[William_H]

My fractional keel stepped Isomat has roots welded to the mast as described above so I take care when lifting the rig as I have heard these are regarded by surveyors as non-repairable if aged. There is a little play but not excessive when the mast is down. There is a plastic insert in the root hole where the pin goes through. Some wear there might increase the movement but once the mast is in position and upper halyard is tight there should be no movement and the spreader should be in compression. I take the spreaders off when ashore for the winter to avoid wind shake damaging the spreader system. I have found Rig-Rite very helpful and they have a large stock of parts.

Be very careful of spreaders in a fractional rig as it is the sweep back of the spreaders that provides push forward to the middle of the mast. (against the pull backward from the intermediate side stays). There is this force pushing the spreader tip forward. This force is taken by the base to spreader connection. So while free play in itself ,may not matter it will move with tension release on each tack so the base does need special attention. I know, I lost a mast through failure of the spreader base to mast attachment. Pop rivets failed with corrosion allowing spreader to swing forward. good luck olewill

 

[Slowtack]

William H, I agree. You have to set it up properly.

 

[akyaka]

The only people who now deal with Isomat masts etc that I have found is Rigrite in the USA as mentioned by Merlin3688. http://www.rigrite.com/index.php.Their catalogue is very comprehensive.

I have found them very helpful in the past

 

[savageseadog]

Be very careful of spreaders in a fractional rig as it is the sweep back of the spreaders that provides push forward to the middle of the mast. (against the pull backward from the intermediate side stays). There is this force pushing the spreader tip forward. This force is taken by the base to spreader connection. So while free play in itself ,may not matter it will move with tension release on each tack so the base does need special attention. I know, I lost a mast through failure of the spreader base to mast attachment. Pop rivets failed with corrosion allowing spreader to swing forward. good luck olewill

Indeed. The Kemp cast alloy spreader roots on their fractional masts use to crack and need to be replaced regularly

 

[langstonelayabout]

I have exactly the same situation at the moment on my Catalina/Isomat mast. I'll PM you.