Volvo Penta saildrive fairing attachment to hull

[yotter]

I am nearing the end of chenging the dreaded Saildrive diaphram on my VP SD130. I had to make a note of which was the old one, because it looked identical in condition to the new one! Anyway, I know that VP recommentd contact adhesive for glueing the fairing to the hull, but I am tempted to use Sika 291i. What does the panel think? Temperature may amso be an issue, its pretty cold now, hopefully a bit warmer soon.

 

[jwfrary]

291i will work but might be a bigger pain when you want to take it off!

if your doing it in the cold the contact adhesive might like a little assistance from a hair drier to help thinks along.

incidentally the royal navy use contact adhesive to stick the rubber acoustic panels to the submarines....they do come off though!

 

[yotter]

Jon,
Many thanks for that, good point about the removal, hopefully not for 7 years . Perhaps the RN (or Babcocks) should try 291i for their tiles.

 

[bigwow]

We used CT1 on ours, I think they are still on, I haven't seen the boat for months

 

[philwebb]

Hi for the VP saildrive fairing I have stopped using the recommended contact adhesive as I found it quite unreliable. I now use Serious Glue from Halfords- much better- I’ve not lost the latest fairing.

 

[scottie]

I am nearing the end of chenging the dreaded Saildrive diaphram on my VP SD130. I had to make a note of which was the old one, because it looked identical in condition to the new one! Anyway, I know that VP recommentd contact adhesive for glueing the fairing to the hull, but I am tempted to use Sika 291i. What does the panel think? Temperature may amso be an issue, its pretty cold now, hopefully a bit warmer soon.

The gaiter should have a mould date on it

 

[yotter]

The gaiter should have a mould date on it

Yes, it should, the new one says 2020, the old one has no date that I can figure out. Should have been changed in 2011 (previous ownership). Have been careful to make sure the date is visable from the aft cabin access panel. The old one was like new!

 

[scottie]

I think that the date stamp was not an original feature

 

[eilerts]

I think PU sealant/glue (Sikaflex, etc) or contact adhesive are both fine. What is important is that you remove all old glue on the hull and sand back to clean gelcoat or primer, and sand and degrease the rubber surface.
I use to dry mount it and trace around with a marker, so I know how wide I have to prepare the surface, to be sure the edge does not land on old antifouling.
If you go for contact adhesive, stretch it tiny bit at you put it on. This reduces the risk of getting a fold. If you happen to have a air roller for laminating, it is perfect for pushing the rubber hard to the hull, which is important.
As Sikaflex takes longer time to cure, I expect there is a risk that the rubber fall down as soon as you go for a cup of tea. Can't say I have experienced this, so perhaps it is really no big problem.
I used Sikaflex the first time I did this, and it fell off during the first season, but I'm pretty sure it was due to poor surface cleaning. Mounted it again with contact adhesive and it stayed on or 9yrs. I have never seen a diaphragm that has failed, or even close. I worst one I have seen was full og 3-5mm bristers, resembled crocodile skin, but was still fine inside. Have a look.

 

[SvenH]

I make my own fairing flaps and bond them using bostik stuff similar to sikaflex. I tried contact adhesive the first time and my flap was gone after the season.

Now I have to remove them myself... I use a oscilating multitool for that, one minute job.
Leaves very little old glue.

Just before putting the new one on I sand the old area and the new flap.

 

[SimonKNZ]

I had the 14-year old diaphragm changed a few months ago and the external flange has already fallen off and is half way down the sail drive leg. Mask and flippers on tomorrow to cut it off then the installer is re-doing next haul-out. Similarly, the old diaphragm was perfect - maybe the old adage "if it ain't broke, don't fix it" applies here. Previous boat was on original diaphragm at 30 years old with no hint of a problem

 

[yotter]

Many thanks for the advise, I will fashion a way to hold the fairing up while I go for my cup of tea. I do feel that I am disturbing a good installation just to replace a diaphram which is as good as new. But I feel I have to do it in case there is an issue and the insurance company asks the obvious question or looks at the date....what date, there was no date, but I guess that indicates the age. Perhaps VP could modify the servive life of the diaphram, they did afterall change the saildrive oil specification from ATF to engine oil after quite a time.

 

[scottie]

I think you hit it on the head more afraid of the cost of not changing it as opposed to the likelihood of it happening

 

[DavidFisher]

Have to replace this rubber fairing on Volvo saildrive leg too.
Have others managed to get new fairing on with prop in place or have you had to remove the propeller. I don't want to tear it trying to get it over the 3rd blade of the prop.
Also has anyone used Bostic 2402 and had good results, ie sucessful long term adhesion?
David

 

[Neeves]

Removing a prop from a Volvo sail drive leg shaft is not a drama. Do not worry about the procedure. Find something else to worry about.

Jonathan

 

[blush2]

The prop was still off, it normally comes home whilst we are out of the water, but would have had to come off to lift the leg when we changed the diaphragm anyway.

 

[scottie]

Prop should be taken off and shaft greased every year
it is well worth it
just watch that the spacer doesn’t stick to it and fall off when you put it down and wonder why the prop is loose