Re: Sand Blasting
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Hi Pat. Before you paint the bottom or apply any coatings, be certain to have the bottom checked with a moisture meter over its entire surface. It states in the Amel owner’s manual in the third section of the users guide several things about using high pressure washing below the waterline. It says to never use more than 1130 psi/80 bars of pressure, always from a distance of more than 8 inches/20cm, and at an angle of 45 degrees and never perpendicular. It is generally recognized that using pressure above 2500 psi is detrimental to any polyester or epoxy resin fiberglass laminate.
Be sure that you have an acceptable level of moisture in the laminates before you proceed to refinishing.
I have seen first hand the detrimental effects that extreme high pressure washing can produce and it is never pretty. If you would find it helpful, give me a call after you get your moisture readings and I’ll give you some advice based on experience that should be helpful.
All the best,
JOEL F. POTTER ~ CRUISING YACHT SPECIALIST, L.L.C.
The Experienced AMEL Guy
UNSURPASSED AMEL MARKETING EXPERIENCE AND PRODUCT KNOWLEDGE
Office 954-462-5869 Cell 954-812-2485
From: main@AmelYachtOwners.groups.io <main@AmelYachtOwners.groups.io> On Behalf Of Patrick McAneny via groups.io
Sent: Tuesday, August 18, 2020 7:54 AM
Subject: Re: [AmelYachtOwners] Sand Blasting
James, There was one area ,about 8 sq. inches where there must have been a void where the first or last layer of fiberglass was partially removed ,the manager said that sand blasting would have opened it up as well. It will be a simple fix and I will be doing about three or four coats of barrier coat . There is no other area where all the paint was removed ,so no damage to the gel coat,after a light sanding the gel coat is as smooth as can be. The yard did not consult with me on power washing as opposed to sandblasting ,which concerned me ,but I am glad they went with it.
This sounds like an interesting option to me and apparently there was no damage done to your gel coat. I like the fact that you avoided using harsh chemicals. You also checked your boats bottom for loose putty and voids in this process whether you realize it, since 5000 PSI can take anything off that is not well attached and can open up voids near the surface! I had the bottom of my boat checked with an ultrasound during the initial surgery looking for voids, delaminations etc. and non were found. That would not be the case on many non Amel hulls. It seems that Amel does a very good job with their laminations in getting out all of the air, especially at the critical gel coat interface. Really glad that this worked out for you.