A HotVac treatment takes under 10 days for a 10 metre boat - removing the anxiety of waiting to know if the boat will dry - getting you back on the water quickly, and reducing the likelihood of osmosis re-occurrence. HotVac will diagnose partial de-lamination and confirm severe hydrolysis breakdown  

Why use HotVac? 
- Reduce drying time to days, even with long term "hopeless cases"
- Remove osmosis and the causes of osmosis
- Restore structural strength to the hull
- Post-cure of new hull builds or hull repair work

What is Osmosis? Osmosis quite simply is the physical process by which a liquid from a weaker medium is drawn through a semi-permeable membrane into a stronger liquid medium. So what does this mean and how does this relate to boat hull damage?

The simple answer is probably not a lot! Contradicting earlier theories, the damage from “osmosis” is not caused by excessive water permeation. There are absolutely no osmotic forces involved as the gelcoat is an absorbing material which can never act as an osmotic membrane! Instead it is the process of hydrolysis, which creates the water soluble corrosive products which in turn create the familiar cavities. (Hydrolysis is the general term given to the reaction of any material with water, for example organic compounds like polyester resin, itself the main constituent of GRP laminates.)

Once the cavities have formed, then excess water will enter giving rise to high moisture readings. This process may normally be slow, but the presence of free acids or alkalis will greatly accelerate it.

The first point to note is that it is the phthallic acid, formed in the process of hydrolysis of polyester resin, which causes the chain reaction and subsequent laminate damage, not the water! The acid forms as water insoluble crystals and cannot be washed out of the laminate as claimed by some. Even after years of hard-standing and weekly washes, the acid will remain in the capillaries and cavities, fixed in styrene and glycol. However, water will react with PVA binders in the laminate, reducing them to acetic acid. It is this that gives the strong smell of vinegar when blisters are burst. Even so, it must be noted that the laminate can become severely damaged before any warning blisters appear.

Osmosis blisters are not only a cosmetic problem. They are the visible sign that the hydrolysis of the polyester has affected at least one laminate layer.By the time the first blister shows, hydrolysed alkali products will have reduced the bond between fibre-glass and polyester deep in the laminate below the water line! This in turn, will have caused a 20-30% loss of structural strength which no “dry and shield” treatment can restore. Without a proper treatment large parts of the laminate layers will sooner or later have larger areas of polyester hydrolysed with only soft wet fibreglass left.

Studies of hundreds of larger hulls with heavy woven roving mats in the laminate have been undertaken. All were found to have numerous sites inside each roving layer and direct evidence of de-laminations deep in the bulk caused by degrees of severe hydrolysis. Significantly most hulls showed no telltale blisters at all!

For further information on “Osmosis” and its chemistry, we do recommend you visit www.osmosisinfo.com and read what Bengt Blomberg has to say. You will be able to buy a copy of his book from that site, which is one of the most comprehensive (and controversial!) on the subject. The comments above are drawn from his text.  

The removal of the gelcoat is the first stage of any Osmosis blistering treatment and peeling is widely accepted as the most cost effective system for guaranteeing an assured repair. The GelPlane has well documented advantages of speed, economy and quality of finish but further, with the dust extraction system the workplace remains clean. GelPlane International provides the product not the peeling service allowing the yard to benefit from convenient work scheduling, quality control and the profitability of working in house.

The GelPlane has many other uses apart from gelcoat removal, for instance the bulk removal of laminate for scarfing in repairs, and in addition provides the opportunity for offsite peeling contracts.  

The hand held GelPlane provides a convenient and controllable method of gelcoat removal. With the vacuum unit it is self contained and requires only an electrical supply for operation. The depth of cut is set by readily adjustable shoulders which position the blades relative to the hull. The blades are standard tungsten carbide slip design and available from a variety of manufacturers. The Bosch drum is driven by an AEG motor so all of the spare parts are locally available.

The GelPlane will peel as easily on concave curves as on convex and is versatile enough to cut over spray rails around skin fittings and between bilge keels. An experienced operator can peel up to 90 square feet per hour without needing to remove the antifouling first. The GelPlane carries the CE mark conforming with European Essential Health and Safety requirements.

The GelPlane is currently available from our worldwide distributors. The machine is supplied complete with a comprehensive Operating and Maintenance manual, tool set and sufficient spares to peel your first 30 foot boat.

We have produced a free demonstration video that should leave you in no doubt as to the machines efficiency, if you would like to receive a copy or if you have any further queries then please do not hesitate to contact us.