Is the hull compromised
Ky/Tenn. area we had waters freeze any where from 1 to 2 inches under the Houseboat's.
Regarding the stand pipe's in these hulls some of which did freeze and issues arose.
The question is those boats where the obvious never occurred. Is it likely the weld the stand pipe could have been compromised or weaken. So down the road normal vibration ware an tare, has this area been compromised enough for concern?
I was given this tip if you fill the stand pipe with cooking oil its lighter than water thus a prevention any thoughts on this ...
I corrected this after east tenn. below pointed out my mistake's, he's correct.
(I posted oil was heavier than water). Also the ice surrounded the boats
How did the water freeze "under the houseboats"? I can see it freezing around the boats, but not under them.
If the welds were done correctly, they will be as strong or stronger than the aluminum around them.
If you pour anything down the standpipe that is heavier than water, it will just keep sinking on out the bottom. If you put something lighter than water, then it should displace the water and more or less stay in place.
Pouring cooking oil down the tube should work, as it would float on top of the water and its weight would push the water out the bottom of the intake tube. What's uncertain here is the likelihood of currents gradually pulling the cooking oil out of the tube.....not sure. I was also concerned about my through-pontoon water pickups freezing and busting the pipe on the inside of the pontoon. Water froze around my boat 3 times over the winter, but my Marine Air worked just fine to keep the heat rolling inside the cabin. So far, I've had no issues.
EastTN. thanks I stand corrected. good to know that there is no need to worry about the welds around the stand pipe due to freezing water.
My boat was at Pluckebaum in 2012 for general maintenance (anodes, pack shafts, paint, etc.). I had a very small leak from a threaded on 90 deg fitting on the top of one of the stand pipes. Their recommendation was to remove the stand pipes and install traditional tru hulls. My leak at the stand pipe must not of been an isolated incident. They removed and installed sea cocks in place of 6 stand pipes. Now when I close the valve it is down near the hull plane and not a foot or so above. I always worried about if the water in a stand pipe could freeze and if so would it split the pipe . With no valve at hull level it is impossible to remove the water from the stand pipe.
What are the thru hulls made of - marelon, bronze, ...?
I have also seen the standpipes with an open topped box welded around them that extends above the waterline. If the standpipe breaks, then the water will just fill the box. It would seem that a combination of traditional thru hulls and the box would the the safest. It would also allow you to replace the thru hull while the boat was in the water.