Blisters adding weight to hull means new propeller to regain speed???

[sailcarole]

My 1986 E-32 received a West Epoxy System hull job in 1988 when the blister problem was first noted, although my water absorption readings were under 10%. Ericson paid half the cost and the "blister problem was solved forever." In south Florida by 1993 the blisters were back. Hundreds of little ones. A surveyor advised me to not treat them until the hull fell into my hand when cleaning.(?!). (Some blisters are larger than a human hand. Do any of you have a similar situation? How much water weight can this hull absorb? If it's 10-15% of original weight, what can be done to increase lost speed?

Spent today reading your forums on propellers, but did not find any E-32 changes to a fixed 3 blade. I'm planning to replace the original 15x 9 with a 3-blade, same size &pitch. The feathering/automatics are too expensive, and I no longer race except against tide and daylight. It can be a long 12-20-hour trip just to get to Miami if I can't maintain five knots. Thanks for input!

 

[toddster]

I can't imagine that the weight of fluid in blisters would be more than a few hundred pounds at the most dire.

That said, according to the scale on the travel lift, my moderately blistered boat weighted almost 3000 lbs more than its catalog weight this winter. I can't really figure that out, unless the operator didn't account for the weight of the slings and blocks. We'll see if there's any difference after drying out for four months.

 

[Loren Beach]

Bottom Lumps and Pitches

My 1986 E-32 received a West Epoxy System hull job in 1988 when the blister problem was first noted, although my water absorption readings were under 10%. Ericson paid half the cost and the "blister problem was solved forever." In south Florida by 1993 the blisters were back. Hundreds of little ones. A surveyor advised me to not treat them until the hull fell into my hand when cleaning.(?!). (Some blisters are larger than a human hand. Do any of you have a similar situation? How much water weight can this hull absorb? If it's 10-15% of original weight, what can be done to increase lost speed?

Spent today reading your forums on propellers, but did not find any E-32 changes to a fixed 3 blade. I'm planning to replace the original 15x 9 with a 3-blade, same size &pitch. The feathering/automatics are too expensive, and I no longer race except against tide and daylight. It can be a long 12-20-hour trip just to get to Miami if I can't maintain five knots. Thanks for input!

Water weight would add very little to the weight of the hull's existing glass laminate material. Very little. Strength can be an issue if a hull laminate has blistering that goes into the glass roving layers as opposed to to usual problem of its being under the gel coat layer or first layer of scrim.

It's been a very long time since that "blister job" was done. Materials and techniques have advanced a lot. Nowadays a yard could used a hot vac to de-moisturize the laminate, after some abrasion of the old layer of resin to remove or reduce it.
I would want to re-do any areas with large blisters. The little dime-size ones can be opened, dried out, and faired in with a good grade of epoxy fairing material, in my limited experience.

Regarding prop pitch -- you will find that the your new three blade will need to be considerable less pitch than the old two blade. As discussed in this thread -
http://www.ericsonyachts.org/infoex...-Prop-Comparisons/page2&highlight=three+blade
--- a three blade for me would be best at about a 9" pitch. While our two boats are similar in displ, you have less waterline. Similar diesel aux. My "swag" is that you would want a 9" pitch at most in a three blade, and maybe even an 8.5".

Another two cent opinon!


LB