Shaving the hull, good idea?

[CapnRal]

How do you determine that is a good idea to shave a hull? And where do I find the right tool(s) for the job? Also, is this an operation that can be undertaken with little or no experience or do I need to apprentice with someone first?

[camaraderie]

You shave the hull when you have bad blisters or extensive gel coat cracking (that does not extend deeper) and you are going to do a complete bottom repair. Not something for amateurs typically. Here's an example of one of the tools you could use and video clips on it in use.
http://www.aittool.com/marineshaver.html

[CapnRal]

Thanks for the info. Mind you I'm not an amateur with tools in general or in paint and paint prep, I just have little experience with fiberglass boats. Looking at the videos it looks as if I could handle it.
Again, Thanks.

[alanl]

Even if you do not agree with the recommendations, the article at http://yachtsurvey.com/BlisterFail2.htm is well worth reading

Regards

Alan

[CDRA]

You may want to read The question of Blisters yet again? from the boat buying forum.

It would appear that a better approach to blisters is to do less.

https://www.yachtworld.com/sealake

[paulk]

If you have enough blisters to be considering "shaving the hull" in your spare time, perhaps a total rebuild of the hull below the waterline is in order? If you own a sawzall, you will find that the builders or previous owners have conveniently marked off exactly where you need to cut, usually in a contrasting color, just above the antifouling paint. Cut off the part below this line and discard it. Build a new lower section out of the same material as the upper section (you don't want incompatibility and flex issues to mar the finish of the topsides) and attach it to the upper portion. Launch, and away you go!
Obviously, a website forum is not the best place to learn about stripping a hull to repair blister damage. There are books about this that go into the details that casual posters may forget to mention, and which may be important to the outcome of your situation. Getting more information is good, but be aware of the possibility of biting off more than one mouthful in this operation.

[T37Chef]

[quote=CDRA]
It would appear that a better approach to blisters is to do less./quote]

I believe this is bad advice. It depends on the situation of your blister problem. Are they structural or cosmetic?

Have a professional blister repair contractor come to the boat and do a laminate profile, cost was about $125, this included filling and fairing the spot in which they took the sample. Not to mention every boater in the yard gave their opinion

[svsirius]

The only way to determine whether or not the hull needs to be 'peeled' is to do a laminate profile test where the hull is measured for moisture and then ground back in stages until a dry laminate is found. This needs to be done by a professional as getting good consitent readings from the moisture meter is key. I your hull is 'dry' to start with then you don't need to go any further.

If the test shows the hull is 'wet' then you need to peel back to dry and build the area back-up. If it were me I and I needed a peel I would have a professional do the peel - they own the tools and know how to use them. And then build it back up my self or pay for the whole job depending on you willingness to work with glass and resin.

[CapnRal]

Thanks but I don't remember mentioning blisters. It just seems to almost be a fad in and around some yards. And people are shelling a lot of money to a very few people for it. I was just thinking of capitalizing on an oportunity. Of course I would want to practice on my own hull rather than some unsuspecting yachty with too much money, which is what I have been seeing happen.
Of course we could start a new thread about blistering but its been done and we need not rehash it here.
http://svfengshui.blogspot.com/

[RichH]

go to yactsurvey.com ----> Blisters, etc. for probably the BEST discussion of osmotic blistering, etc.
When to peel? when the hull is showing extensive hydrolysis failure of the laminate structure (usually hydrolysis thats developing 'deeper' than just the cosmetic gelcoat and matting layers ... ie.: evidence of penetrationn into the structural roving layers.

Hull that is 'wet' .... BS all laminate structure may become wetted due to chemical equilibrium. Its when the 'wet' propagates hydrolysis (analogous to rusting in metals) and the structure is 'chemically degrading' is when you need to plance or 'shave' it off and start over. Most blister repair is probably just expensive 'hype'. When in doubt get some laboratory analysis performed to examine for actual hydrolysis, etc.
Go to the Pescoe website at www.yachtsurvey.com .... educate yourself as well as you can, then make your decision.