Fly Navy Posted February 20, 2019 Report Share Posted February 20, 2019 (edited) Please...............no tittering in the cheap seats, now: I am told (by an ex- houdini hatch salesman) that Houdini hatch's are the quickest way to producing condensation inside a boat - ever! Even faster than single glazed windows. So........... Thinking outside the box........ What if I fitted a suitably sized VELUX triplex (openable) window into the superstructure (ceiling)????/ No condensation and tough enough to walk on (closed of course!). Tittering can commence together with any constructive comments please ? Edited February 20, 2019 by Fly Navy Link to comment Share on other sites More sharing options...
Keeping Up Posted February 20, 2019 Report Share Posted February 20, 2019 We have a conventional houdini hatch; I cut some twin-walled plastic to fit and glued it to the metal frame of the opening window, so it opens with it. With the glass and plastic, and tape around it to stop airflow inside it, it is effectively triple-glazed so we get no condensation except from the fixed part of the metal frame. 1 Link to comment Share on other sites More sharing options...
mrsmelly Posted February 20, 2019 Report Share Posted February 20, 2019 13 minutes ago, Fly Navy said: Please...............no tittering in the cheap seats, now: I am told (by an ex- houdini hatch salesman) that Houdini hatch's are the quickest way to producing condensation inside a boat - ever! Even faster than single glazed windows. So........... Thinking outside the box........ What if I fitted a suitably sized VELUX triplex (openable) window into the superstructure (ceiling)????/ No condensation and tough enough to walk on (closed of course!). Tittering can commence together with any constructive comments please ? I had one on my widebeam. Worked well. 1 Link to comment Share on other sites More sharing options...
blackrose Posted February 20, 2019 Report Share Posted February 20, 2019 (edited) 6 minutes ago, Keeping Up said: We have a conventional houdini hatch; I cut some twin-walled plastic to fit and glued it to the metal frame of the opening window, so it opens with it. With the glass and plastic, and tape around it to stop airflow inside it, it is effectively triple-glazed so we get no condensation except from the fixed part of the metal frame. Can't help thinking that if the consumer has to bodge a solution it sort of shows that the product has a basic design flaw. I sometimes end up bodging things that I purchase to get them to work properly, but it does irk me somewhat that the person paid to do it hasn't done their job and left it to me. Edited February 20, 2019 by blackrose 1 Link to comment Share on other sites More sharing options...
Keeping Up Posted February 20, 2019 Report Share Posted February 20, 2019 6 minutes ago, blackrose said: Can't help thinking that if the consumer has to bodge a solution it sort of shows that the product has a basic design flaw. It's a basic design flaw of all single-glazed windows that they aren't double-glazed! 2 Link to comment Share on other sites More sharing options...
blackrose Posted February 20, 2019 Report Share Posted February 20, 2019 (edited) 15 minutes ago, Keeping Up said: It's a basic design flaw of all single-glazed windows that they aren't double-glazed! Not really Allan. In terms of condensation, single glazed cabin windows will drip into the gutter running around the perimeter - a feature of most modern manufactured boat windows. You'll still get a bit from the frames assuming there is no thermal break but nothing like the quantities of condensation you'll get dripping into the boat from a single glazed horizonal Houdini hatch. That's why you've had to come up with your own solution for the hatch (which by the way is admirable), but probably not for your single glazed windows. Edited February 20, 2019 by blackrose Link to comment Share on other sites More sharing options...
GUMPY Posted February 21, 2019 Report Share Posted February 21, 2019 Thanks to polycarb secondary glazing we get no condensation on our hatch nor on our windows. Way to go! Link to comment Share on other sites More sharing options...
Naughty Cal Posted February 21, 2019 Report Share Posted February 21, 2019 We have a couple of Bomar hatches on our boat and get next to no condensation on them. http://pompanettellc.com/current-catalog/hatches/2000-series-high-pro-hatch/ Only on the very coldest of nights do we get a little moisture on the frames. But we make sure that our boat has plenty of ventilation at all times which is the key to avoiding excess amounts of condensation. Link to comment Share on other sites More sharing options...
Fly Navy Posted February 21, 2019 Author Report Share Posted February 21, 2019 Mmm. So it seems it's not such a silly idea after all, Watson?? I was also told by an "expert" that on a 60 foot NB, with the sun blazing down on one side and not the other, the side in sun - expands up to 1 inch. That's 2mm per foot length of boat that moves. This causes cracks in grouting, tiles and above all else, is the main reason for double glazing units failing prematurely (blow). Quell surprise. FN Link to comment Share on other sites More sharing options...
Naughty Cal Posted February 21, 2019 Report Share Posted February 21, 2019 51 minutes ago, Fly Navy said: Mmm. So it seems it's not such a silly idea after all, Watson?? I was also told by an "expert" that on a 60 foot NB, with the sun blazing down on one side and not the other, the side in sun - expands up to 1 inch. That's 2mm per foot length of boat that moves. This causes cracks in grouting, tiles and above all else, is the main reason for double glazing units failing prematurely (blow). Quell surprise. FN Don't put any windows in it then. They wont fail that way. Link to comment Share on other sites More sharing options...
WotEver Posted February 21, 2019 Report Share Posted February 21, 2019 1 hour ago, Fly Navy said: I was also told by an "expert" that on a 60 foot NB, with the sun blazing down on one side and not the other, the side in sun - expands up to 1 inch He’s out by rather a large factor. The coefficient of expansion for Steel is around 12x10-6 per degree C. So a difference of temperature of 20C (unlikely I would have thought) gives 240x10-6, or 0.000240. Over 60ft that gives a difference in length of 0.0144ft, or 0.17”. 1 Link to comment Share on other sites More sharing options...
David Mack Posted February 21, 2019 Report Share Posted February 21, 2019 2 hours ago, Fly Navy said: and above all else, is the main reason for double glazing units failing prematurely (blow). Since sealed double glazing units float within the window frame, I think it unlikely that expansion and contraction of the shell would be a significant factor. Link to comment Share on other sites More sharing options...
X Alan W Posted February 21, 2019 Report Share Posted February 21, 2019 (edited) 3 hours ago, Fly Navy said: Mmm. So it seems it's not such a silly idea after all, Watson?? I was also told by an "expert" that on a 60 foot NB, with the sun blazing down on one side and not the other, the side in sun - expands up to 1 inch. That's 2mm per foot length of boat that moves. This causes cracks in grouting, tiles and above all else, is the main reason for double glazing units failing prematurely (blow). Quell surprise. I think your "expert" is feeding you 'Duff info" having worked on the SR 71 at Lockheeds Skunk Works Famous for it's dripping fuel tanks when standing to be taken up at Mach3 'ish" granted it was titanium not steel & for the life of me can't remember the expansion rate"was some time ago " factors, the actual #'s were much nearer to the quote in post #11 If the figures from your source'were correct sunny day boating would be even more difficult( thinking lock width/boat beam ?) Edited February 21, 2019 by X Alan W Link to comment Share on other sites More sharing options...
Fly Navy Posted February 21, 2019 Author Report Share Posted February 21, 2019 Damn steel expansion issue stole the show. What about Velux windows being fitted? Anyone else? Link to comment Share on other sites More sharing options...
pearley Posted February 21, 2019 Report Share Posted February 21, 2019 11 hours ago, Loddon said: Thanks to polycarb secondary glazing we get no condensation on our hatch nor on our windows. Way to go! Same here. Link to comment Share on other sites More sharing options...
Phil Ambrose Posted February 21, 2019 Report Share Posted February 21, 2019 2 Houdini hatches double glazed during cold months, a simple piece of acrylic held over the hole in the head lining with swivel plastic clips. Works fine but yes would agree that without some form of DG Houdini hatches "rain" Phil Link to comment Share on other sites More sharing options...
Ex Brummie Posted February 21, 2019 Report Share Posted February 21, 2019 Definition of an expert: an ex is a 'has been', a spurt is a 'drip under pressure.' 1 Link to comment Share on other sites More sharing options...
Dr Bob Posted February 21, 2019 Report Share Posted February 21, 2019 10 hours ago, WotEver said: He’s out by rather a large factor. The coefficient of expansion for Steel is around 12x10-6 per degree C. So a difference of temperature of 20C (unlikely I would have thought) gives 240x10-6, or 0.000240. Over 60ft that gives a difference in length of 0.0144ft, or 0.17”. Our dark blue roof got to 65 deg C in the sun most days last summer. The side less so but maybe + 30 deg from the shaded side. Fried all or eggs on the roof. Saved on washing frying pans. Link to comment Share on other sites More sharing options...
Boater Sam Posted February 22, 2019 Report Share Posted February 22, 2019 3 Houdinis, condensation is bad but not on the glass but on the alloy frames particularly when it rains and the temperature drops a bit. They need to be constantly just open on the catches to avoid it,. I've told the wife to stop breathing as it makes it worse but will she listen? Link to comment Share on other sites More sharing options...
Naughty Cal Posted February 22, 2019 Report Share Posted February 22, 2019 4 hours ago, Boater Sam said: 3 Houdinis, condensation is bad but not on the glass but on the alloy frames particularly when it rains and the temperature drops a bit. They need to be constantly just open on the catches to avoid it,. I've told the wife to stop breathing as it makes it worse but will she listen? Ventilation is the key to reducing or omitting completely condensation. We very rarely get condensation on board as we keep all of the windows and hatches cracked open when we are onboard. The only time we get condensation is if we forget to open a window or hatch. Link to comment Share on other sites More sharing options...
Ex Brummie Posted February 22, 2019 Report Share Posted February 22, 2019 What sort of ;expert' quotes his findings in mixed measurements; 2mm per foot . Surely the length of the boat has no bearing on the amount of expansion of a given material in identical conditions Link to comment Share on other sites More sharing options...
Boater Sam Posted February 22, 2019 Report Share Posted February 22, 2019 (edited) 10 minutes ago, Ex Brummie said: What sort of ;expert' quotes his findings in mixed measurements; 2mm per foot . Surely the length of the boat has no bearing on the amount of expansion of a given material in identical conditions The expert is in quote marks presumably because there is some doubt, I read it as it is the one that spoke to Fly Navy. I rather like mixed measures, 2 parts rhum to 5 parts Coke. As to expansion having no bearing on length, for the same material why not? Is the steel going to expand more or less because it is sections welded together? Or if the boat is longer, is the steel more expansive? ( pun intended ) Does a tube expand more than a solid bar of the same material? Edited February 22, 2019 by Boater Sam added more Link to comment Share on other sites More sharing options...
Phil Ambrose Posted February 22, 2019 Report Share Posted February 22, 2019 (edited) 14 minutes ago, Ex Brummie said: What sort of ;expert' quotes his findings in mixed measurements; 2mm per foot . Surely the length of the boat has no bearing on the amount of expansion of a given material in identical conditions Possibly to couch his response in figures that can be related to, we all think of the length of a boat on terms of feet, adverts are generally for boats of X feet. Of course we should be using metric but hey it's a less than perfect world Phil Edited February 22, 2019 by Phil Ambrose Link to comment Share on other sites More sharing options...
JJPHG Posted February 22, 2019 Report Share Posted February 22, 2019 21 hours ago, WotEver said: He’s out by rather a large factor. The coefficient of expansion for Steel is around 12x10-6 per degree C. So a difference of temperature of 20C (unlikely I would have thought) gives 240x10-6, or 0.000240. Over 60ft that gives a difference in length of 0.0144ft, or 0.17”. I remember when I was researching a case once (a good few years ago) that the temperature difference can be as high as 50C, but that was in a slightly more favourable latitude and was with a very dark matt paint. That said your point is still very valid and even under these extreme and favourable conditions the expansion is not going to get anywhere close to the 1" quoted Link to comment Share on other sites More sharing options...
Boater Sam Posted February 22, 2019 Report Share Posted February 22, 2019 Over 6" for Concorde as I remember. Then narrowboats don't do Mach 2.1 Sadly, neither does Concorde anymore. My boat is now faster. 1 Link to comment Share on other sites More sharing options...
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