Hi Alex. Great work, you are going to get a good restoration job there keep at it. I’m sure this thread on another forum some of our members are on will be of interest to you.
There are posters more experienced with glass than me on here that I’m sure will have good advice.
Keep up the progress reports.
Meant to ad that the old antifoul dust is pretty toxic as I understand it. Not withstanding that a good respirator with dust filter is needed for glass anyway, be careful with the antifoul dust and disposal.
You might also check our thread on asbestos if your working inside. Not likely in 563s but be aware if sanding filleted joins. There was a wide range of construction sites and constructors on these boats and who knows what practices were used by who.
Ozzie
Investigator #143 "SPRITZIG II"
The Mariner - “It’s too strange here. It doesn’t move right." ...
Enola - “Helen said that it’s only land sickness."
Waterworld (1995)
Hello Alex. Did David give you information to work with ? I think he did. What he would have told you will be very good advice. Just looking at your photos, especially below the water line, I just wonder how far you have had to grind into the fibreglass. If the grinding has just got through the outer layer which is the gel coat, white in colour, then the use of epoxy bog would be fine to fill it. However in one of the photos, it looks like you have had to grind into the actual fibreglass. If this is ground away too much, you will need to fibreglass over it to restore the hull thickness. Because the boat was badly effected by osmosis, once it is ground back, washed out with acetone and thoroughly dry, the best way forward is to seal the old fibreglass off using epoxy resin. If you have to add a layer or two of fibreglass over where you have ground it, then doing that using epoxy resin will do the repair as well as seal off the old glass. If you need to use a filler to restore a fair hull shape and you have only ground into the outer layer, that is, the gel coat, then you can use epoxy resin with a filler powder mixed into it which thickens the resin so that it can be applied the same as body filler with a plastic spreader. This epoxy type of filler is easy to sand to get a nice fair surface.
Once the whole area is done, then it should be coated with an epoxy 2 pack paint which can be applied using a mohair roller and tip it off with a good quality brush as you go. Best for you to search on U TUBE on how this is done.
The most important thing is that if you have ground deep into the fibreglass of the hull, that you restore the strength and thickness of the hull by applying actual fibreglass to those areas. The type of fibreglass you use with epoxy is not just normal chop strand mat. Best to get advice from a fibreglass shop on the correct materials to use, or I can advise you. Hope you understand this, if not, you can send me a private message if you like. Good luck with it and as Ozzie said, use a really good respirator as the dust from this type of grinding is no good for you if breathed in.
Just bye way of explanation, the boat was built using polyester resin. This resin, although it sets hard etc, is not 100 percent water proof. A small percentage of the resin used to build the boat actually does not fully set. When salt water reacts with this UN cured resin, this is what causes osmosis. It's a chemical action and it produces a sticky substance which forms a blister just below the fibreglass and it eats away at the fibres of the fibreglass. This is what has happened to your boat, although on a fairly large scale. The fix is to burst the blisters or in your case grinding it away, wash all traces of the chemical smelling liquid away, make sure its fully dried out and then sealing with epoxy. The reason you use epoxy is because it's a much better resin in as much as it is completely impervious to water, so it should not happen again after being fixed correctly.
This is what you are doing .
Epoxy resin can be applied over polyester, but polyester can not successfully be applied over epoxy. This means that once you use epoxy, then any future repairs must also be carried out using epoxy.
Cheers
Also, when using epoxy resin, always use disposable or rubber gloves as uncured epoxy resin in your hands will cause a dermatitis which is really inconvenient and annoying
Regards Peter
Regards PeterT
" Sail-La-Vie," # 114
"Believe me, my young friend, there is nothing - absolutely nothing - half so much worth doing as simply messing about in boats."
