Aluminium IFR problem 1

[prashanth5723]

Hi.
Just came across an AIFR which has double wiper seal. The seal material is polyurethane. The problem in that IFR is product is oozing through some portions of deck sheets. The condition of pontoons is good. Mean to say it is not punctured. Cant figure out why the product is oozing when the tank is filled everytime. Please give some suggestions regarding this problem. Thanks in advance.

 

[IFRs]

Your problem is simple in principle - the liquid level is too high in those areas. That's the only way liquid can get through the deck seams from the underneath. By code, the pontoons should be only half submerged, but they are more than that in those areas. You should be able to see float lines on them. Normally the deck seams are about 1" to 3" above the top of the pontoons so in those areas the deck is submerged over the top of the pontoons. Why is this? Many reasons: usually poor design ( read: marginal buoyancy and wek beams ) to start with combined with poor distribution of buoyancy, excessive seal friction usually from tight rim spaces, weak deck beams in critical areas, weak perimeter sections in critical areas, legs freezing to the bottom, excessive buildup of scale or sand on top of the deck, etc. Another thought: the deck seams are supposed to be vapor tight, if they are not even liquid tight, you probably have a very cheap, just barely meets code ( or does not really meet code ) or poorly installed deck. More details such as pontoon size and length, sheet width, type of pontoon-to-pontoon connection, perimeter rim configuration, type of supports, age ( if known ) and cross section of beam and clamp and type of fastener used to clamp the skins can help identify the make and model and help you decide if it is worth keeping or not. I suspect it is not worth keeping.