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Hull Blisters
I've dealt with hull blisters and have finally decided that they are
normally no big deal. I have never heard of hull failure from them and they seem to be simply a cosmetic problem. As far as drag goes, my fixed prop causes more drag. However, some ppl really hate em and go so far as to PEEEEEEEEELLLL their gelcoat (sounds really painful) dry the matting and re-gelcoat. I call this the Peel 'n Pray method cuz most offen the blisters return. Its just too hard to remove all the water from the matting even with heaters n such. Once, I took an electric heat gun and applied it about 4" from a blister (through the gelcoat)and was amazed at how much water came out of the blister (This was after 2 months of drying). Clearly, passive drying dont work. SO: Useless idea #3727 Peel only in narrow strips in a grid pattern to allow moisture to exit and apply heat to the grid squares. However, heating the glass is inefficient when you really want to heat the water. Instead, use microwaves which couple to polar molecules such as water and dont couple too well to the glass or resin (ie, you only heat the water). You could measure the microwave intensity inside the boat at different places as a function of time to determine dryness. The moisture would attenuate the waves and a dry hull would not. |
Hull Blisters
Parallax wrote:
I've dealt with hull blisters and have finally decided that they are normally no big deal. I have never heard of hull failure from them and they seem to be simply a cosmetic problem. As far as drag goes, my fixed prop causes more drag. However, some ppl really hate em and go so far as to PEEEEEEEEELLLL their gelcoat (sounds really painful) dry the matting and re-gelcoat. I call this the Peel 'n Pray method cuz most offen the blisters return. Its just too hard to remove all the water from the matting even with heaters n such. Once, I took an electric heat gun and applied it about 4" from a blister (through the gelcoat)and was amazed at how much water came out of the blister (This was after 2 months of drying). Clearly, passive drying dont work. SO: Useless idea #3727 Peel only in narrow strips in a grid pattern to allow moisture to exit and apply heat to the grid squares. However, heating the glass is inefficient when you really want to heat the water. Instead, use microwaves which couple to polar molecules such as water and dont couple too well to the glass or resin (ie, you only heat the water). You could measure the microwave intensity inside the boat at different places as a function of time to determine dryness. The moisture would attenuate the waves and a dry hull would not. Gosh, you have a LOT of ideas..... Because I think microwaves belong a long distance from people, I prefer the methods used 'round here. ALL depend upon a dry bilge, since water sitting in the bilge will keep the glass wet. The rankings are increasing level of severity. 1) Plastic draped over the hull to keep new water away. 2) A 100 watt bulb in the mostly-sealed cabin. 3) A dehumidifier in the mostly-sealed cabin, draining through an open through hull. 4) Plastic to the ground, a space heater under the hull 5) Plastic and a spacer taped closely to the hull and a vacuum pulled. Thus, I think #3727 should be filed as useless. -- Jere Lull Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD) Xan's Pages: http://members.dca.net/jerelull/X-Main.html Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/ |
Hull Blisters
One more... I used this and it worked great. http://www.hotvac.com/ I've
posted the summary a few times of all the work, but I'll post it again if anyone's interested. "Jere Lull" wrote in message ... Parallax wrote: I've dealt with hull blisters and have finally decided that they are normally no big deal. I have never heard of hull failure from them and they seem to be simply a cosmetic problem. As far as drag goes, my fixed prop causes more drag. However, some ppl really hate em and go so far as to PEEEEEEEEELLLL their gelcoat (sounds really painful) dry the matting and re-gelcoat. I call this the Peel 'n Pray method cuz most offen the blisters return. Its just too hard to remove all the water from the matting even with heaters n such. Once, I took an electric heat gun and applied it about 4" from a blister (through the gelcoat)and was amazed at how much water came out of the blister (This was after 2 months of drying). Clearly, passive drying dont work. SO: Useless idea #3727 Peel only in narrow strips in a grid pattern to allow moisture to exit and apply heat to the grid squares. However, heating the glass is inefficient when you really want to heat the water. Instead, use microwaves which couple to polar molecules such as water and dont couple too well to the glass or resin (ie, you only heat the water). You could measure the microwave intensity inside the boat at different places as a function of time to determine dryness. The moisture would attenuate the waves and a dry hull would not. Gosh, you have a LOT of ideas..... Because I think microwaves belong a long distance from people, I prefer the methods used 'round here. ALL depend upon a dry bilge, since water sitting in the bilge will keep the glass wet. The rankings are increasing level of severity. 1) Plastic draped over the hull to keep new water away. 2) A 100 watt bulb in the mostly-sealed cabin. 3) A dehumidifier in the mostly-sealed cabin, draining through an open through hull. 4) Plastic to the ground, a space heater under the hull 5) Plastic and a spacer taped closely to the hull and a vacuum pulled. Thus, I think #3727 should be filed as useless. -- Jere Lull Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD) Xan's Pages: http://members.dca.net/jerelull/X-Main.html Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/ |
Hull Blisters
Jere Lull wrote:
Because I think microwaves belong a long distance from people,... I think #3727 should be filed as useless. There may be valid reasons the idea won't work but a microwave phobia isn't one of them. |
Hull Blisters
"Keith" wrote in message ...
One more... I used this and it worked great. http://www.hotvac.com/ I've posted the summary a few times of all the work, but I'll post it again if anyone's interested. "Jere Lull" wrote in message ... Parallax wrote: I've dealt with hull blisters and have finally decided that they are normally no big deal. I have never heard of hull failure from them and they seem to be simply a cosmetic problem. As far as drag goes, my fixed prop causes more drag. However, some ppl really hate em and go so far as to PEEEEEEEEELLLL their gelcoat (sounds really painful) dry the matting and re-gelcoat. I call this the Peel 'n Pray method cuz most offen the blisters return. Its just too hard to remove all the water from the matting even with heaters n such. Once, I took an electric heat gun and applied it about 4" from a blister (through the gelcoat)and was amazed at how much water came out of the blister (This was after 2 months of drying). Clearly, passive drying dont work. SO: Useless idea #3727 Peel only in narrow strips in a grid pattern to allow moisture to exit and apply heat to the grid squares. However, heating the glass is inefficient when you really want to heat the water. Instead, use microwaves which couple to polar molecules such as water and dont couple too well to the glass or resin (ie, you only heat the water). You could measure the microwave intensity inside the boat at different places as a function of time to determine dryness. The moisture would attenuate the waves and a dry hull would not. Gosh, you have a LOT of ideas..... Because I think microwaves belong a long distance from people, I prefer the methods used 'round here. ALL depend upon a dry bilge, since water sitting in the bilge will keep the glass wet. The rankings are increasing level of severity. 1) Plastic draped over the hull to keep new water away. 2) A 100 watt bulb in the mostly-sealed cabin. 3) A dehumidifier in the mostly-sealed cabin, draining through an open through hull. 4) Plastic to the ground, a space heater under the hull 5) Plastic and a spacer taped closely to the hull and a vacuum pulled. Thus, I think #3727 should be filed as useless. -- Jere Lull Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD) Xan's Pages: http://members.dca.net/jerelull/X-Main.html Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/ Has anybody ever seen a case of hull failure due to blisters? I have never heard of such. |
Hull Blisters
Actually, I'm surprised that the racers haven't snapped to this yet.
Golf ball manufacturers sure did a long time ago. Don W. -- who is not a hydrodynamicist ;-) Larry W4CSC wrote: As to drag, a dimpled hull is FAR less drag than a smooth one that creates no eddy currents. Watch the jetski racers draggin' their race boats down the beach to roughen up the surface and break surface tension because they know it will go faster.....and it does. |
Hull Blisters
I believe that Jimmy Connors did it with a product from 3M called
"sharkskin." I also heard that the sailboat racing circuit had declared it illegal. "Don W" wrote in message . .. Actually, I'm surprised that the racers haven't snapped to this yet. Golf ball manufacturers sure did a long time ago. Don W. -- who is not a hydrodynamicist ;-) Larry W4CSC wrote: As to drag, a dimpled hull is FAR less drag than a smooth one that creates no eddy currents. Watch the jetski racers draggin' their race boats down the beach to roughen up the surface and break surface tension because they know it will go faster.....and it does. |
Hull Blisters
Parallax wrote:
Has anybody ever seen a case of hull failure due to blisters? I have never heard of such. I heard one story, but there were so many "heard it from"s that it could well be an urban (nautical?) legend. As I recall, there are some very close approximations on Dave Pascoe's site..... http://www.yachtsurvey.com/blisters.htm On the main site, I believe I saw a disintegrated powerboat that wasn't exactly blisters, but was a close relative. Could also have been in one of the BOAT/U.S. publications. -- Jere Lull Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD) Xan's Pages: http://members.dca.net/jerelull/X-Main.html Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/ |
Hull Blisters
Only one flaw in your arguement "drying the hull out generally doesn't work
ery well. What you are trying to get rid of is not only the moisture, but also the hydrscopic chemicals that are present. Just drying your boat out won't do the job. You need to draw out the chemicals and remove them. Other wise all that will happen is more moisture will be introduced into the laminate by the drying process. Unless the laminate is fully saturated, you'll do just as good a job by "peeling" and then washing the hul down with Alcohol or acetone. (your trying to strip those chmicals from the surface rather than attempt to "dry it out". Once that's been done you cna quickly recoat the hull. Don't waste your time waiting for it to "dry out" that will never happen. Pierre "Parallax" wrote in message om... I've dealt with hull blisters and have finally decided that they are normally no big deal. I have never heard of hull failure from them and they seem to be simply a cosmetic problem. As far as drag goes, my fixed prop causes more drag. However, some ppl really hate em and go so far as to PEEEEEEEEELLLL their gelcoat (sounds really painful) dry the matting and re-gelcoat. I call this the Peel 'n Pray method cuz most offen the blisters return. Its just too hard to remove all the water from the matting even with heaters n such. Once, I took an electric heat gun and applied it about 4" from a blister (through the gelcoat)and was amazed at how much water came out of the blister (This was after 2 months of drying). Clearly, passive drying dont work. SO: Useless idea #3727 Peel only in narrow strips in a grid pattern to allow moisture to exit and apply heat to the grid squares. However, heating the glass is inefficient when you really want to heat the water. Instead, use microwaves which couple to polar molecules such as water and dont couple too well to the glass or resin (ie, you only heat the water). You could measure the microwave intensity inside the boat at different places as a function of time to determine dryness. The moisture would attenuate the waves and a dry hull would not. |
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