Cracked beam under mast?

[Wansworth]

What about an “H” beam…….drill hoes in it to keep the weight down and or be useful to hang things on

 

[Refueler]

The spruce bit was referring to wing spars. For a boat, any decent hardwood.
Going back to ply. The upper and lower laminates in a beam are the ones doing the work, the middle ones just keep them apart and stable, so ply would be ok there.

I would not cut the ply as horizontal laminates - where each layer sits on top of previous - that way the 'grains' of each lamination are not vertical in any to counter the deck compression. I would cut the ply so that they sit as vertical layers so that half the inner laminations in the ply are vertical as 'webs' ..

Adding layers of ply can be set so that maximum compressive support is made.

 

[Lizman]

Hello,

Finally found time to have the boat hauled out.

I realize now that cutting out the old beam and replacing with a laminate is probably the best way forward rather than trying to bodge it with ss angle, when i would still have to use resin to back-fill any gaps.

The lamination will be done in-situ with 6mm ply ? and some hardwood stuff if i can find it, using thickened resin, and screwing each layer with small screws to expedite the work.

The major concern I have is dealing with the fibre dust. I have a good mask and face shield which will help, but the rest of the boat is going to be covered to some extent. I am going to stow all the loose stuff and cover the radio, but what other precautions should I take? I would also welcome any tips or tools that might come in handy. I was going to use my pad saw to try and cut out the beam, but there are multi tools/dremels out there which might be a good idea?

Also, how do I prep the area under the old beam before i apply the first layer of laminate?

Best Wishes
Philip

 

[penberth3]

.....The major concern I have is dealing with the fibre dust. I have a good mask and face shield which will help, but the rest of the boat is going to be covered to some extent. I am going to stow all the loose stuff and cover the radio, but what other precautions should I take? I would also welcome any tips or tools that might come in handy......

If you want to preserve your health, power tools should have proper dust extraction built in, connected to a good vacuum filter unit, i.e. not a lash-up with a car vac or something like that.

 

[Wansworth]

What about a mound for the beam and laminate off the boat,no overhead work

 

[DownWest]

What about a mound for the beam and laminate off the boat,no overhead work

Yes, if you can make a simple pattern it is much easier to lam the beam on the bench. Not least, because the 'wet' laminates are quite slippery and difficult to get into position.
Re the dust, cutting out the old stuff really needs good extraction. Virtually all tools now have proper shrouds for connection to a vac. But, a spare hand holding a nozzle next to the work is very effective. Not to mention the heap of covid masks coming in useful.

 

[Wansworth]

There was a couple up in Alaska who did a complete internal makeover of a Albin Vega including mast beam……don’t recall but it will be on YouTube somewhere

 

[thinwater]

Jack it up. Grind clean, removing much of the roving. Relaminate it with unidirectional, the way it should have been done in the first place. I have done this before on trimarans with a similar structure. Easier than the faffing about that is described.

This is no place for roving. Just get the right materials.

 

[Lizman]

Hi thin water,

Please excuse my ignorance but what does 'Relaminate it with unidirectional...' mean? Are you referring to the glass fibre used afterwards to encapsulate the new beam, or the grain of the wooden laminate?

Regards
Philip