| Subject: |
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BANJERS' HYDROLYSIS / BLISTERING FACTS & PROBLEMS SOLVING |
| Name: |
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Guillermo Gefaell |
| Date Posted: |
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Oct 6, 05 - 9:10 AM |
| Email: |
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bmccommodore@banjer37.net |
| Message: |
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BANJERS' HYDROLYSIS / BLISTERING FACTS & PROBLEMS SOLVING, by Guillermo.
A.- Some facts:
1.- Banjers are 30+ years old boats. If a Banjer has been kept most (or all) of its life afloat, and a proper hydrolysis treatment has not been already done, the hull laminate will be saturated with water (which is not a problem in itself) and some kind of hydrolysis/blistering has to be suspected, if not already evident.
2.- Blistering is a consequence of hydrolysis processes taking place close to the surface of the hull.
3.- Measuring with a moisture meter may give lectures in the "red" scale, indicating water saturation of the outer layers, but this may or may not imply hydrolysis problems and indicates nothing about hidden deeper hydrolysis problems.
4.- Banjers kept ashore for the autuum-winter season (either in cold or hot climates), most probably won't have developed any kind of hydrolysis.
5.- If blisters appear in the hull, first check if they are in the outer layer, or if they affect the interior layers (As is the case of Marie, related upwards in this page) by opening some with a sander, before proceeding with repairs. This will give you a clue about the necessary deepness of repairs.
6.- Hydrolysis fluids exiting the laminate, reduced resin and glass fiber clarity or reduced resin hardness, even with not blistering showing, indicate a most probable hydrolysis of the internal layers .
7.- Deep laminate hidden hydrolysis is worse than surface blistering.
8.- Letting the hull to dry in open air, even with the gel-coat peeled off, does not eliminate glycols, acidic spots, etc. from the internal laminate, as well as does not solve eventual delaminations already caused by hydrolysis. Even curing wtih hot and vacuum does not solve this last problem.
9.- Hydrolysis in a Banjer -If present at all- most probably is affecting only the outer layers of the laminate, four of them at its most. The rest of the laminate should be in fairly good condition.
B.- What to do...?
If you want to definitively solve hydrolisis/blistering problems in your Banjer (Well, not eternally you know, but for a most rewarding very long period of time, indeed), I recommend you to go for an hydrolysis/osmosis treatment as follows, either if your Banjer's hull shows blisters or not:
1.- Peel off all the old gel coat, even if it seems in good shape and no blisters appear.
2.- Check for hydrolisis fluids exiting the laminate. Do some testing, sanding of the outer three-four laminate layers, in several small locations around the hull (You may use actual blisters spots if they are present), to check for internal delamination and adecuate transparency & hardness of resin-fibres, in order to evaluate if you have to remove the outer layers or not, and how many.
3.- REMOVE, with no remorse, all damaged layers (if any), till you find sound laminate.
4.- Re-laminate whatever has been taken off, using vinylester resins and good quality fiber mats.
5.- In case only very little glass was necessary to have been removed, because layers were mostly OK, don't be shy and laminate an extra outer layer of vinylester & 600 gr/m2 mat.
6.- Apply an outer barrier of 0.75 mm vinylester resins (You'll need up to six rolled coats for this).
7.- Apply two coats of your favourite antifouling and...
8.- Enjoy your Banjer for many years to come!
You can do these works by yourself if you have enough time & skills, or hire the services of a proffesional to do them precisely as recommended here. |
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