We get a lot if inquires here at Van's about the use of the sloshing compound (RANDOLF 912) referred to in the older construction manuals. At one time, this was considered a good idea for two reasons. One, it provided a way of fixing any pinhole leaks that may have developed in the riveting of the tanks. Second, it may provide some protection for the PRO-SEAL against formulations of auto fuel.
The problem that has arisen over the last few years is that in a few tanks for some unknown mysterious reason the slosh has started to come loose and accumulate in the gascolator screens of a few aircraft.
We now feel that the consequences outweigh the benefits of the slosh and for that reason no longer recommend its use. A good job of riveting with PRO-SEAL is more than satisfactory in sealing the tanks.
For those who have used the slosh and want to get it out, it is necessary to flycut a 3-4" hole in each bay of the fuel tank baffle so that you can reach in physically and remove the compound. Some solvents like Acetone can soften it but we have found nothing so far that works better than scraping it out. When you have all of it out that you can, then a simple plate of .040 aluminum can be pop riveted with PRO-SEAL over each of the access holes using blind pop rivets.
Tom @ VAN's.
--- End of forwarded message from "VAN's AIRCRAFT"
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