Tank Baffle/Skin Leak

doug_rv7 · #1 11-27-2006, 08:15 PM

I performed my tank leak test today (balloon method, left tank). Unfortunately I wasn't generous enough on the pro-seal when installing the rear baffle. I have two leaks on top. One in the middle and one just on the inside of the outboard rib. I also have a leak in the middle bottom. In the areas mentioned, bubbles appear between the skin and the baffle flange.
What do you think would be the best long term resolution to these leaks?

Doug

kentb · #2 11-28-2006, 12:39 PM

If the leak is not to large (mine just made a small stream of bubbles). Vans leak check documentation states to use locktite to seal it. It worked for me.
I can't remember the loctite type, but could look it up tomorrow if you need me to.

Kent

Stephen Lindberg · #3 11-28-2006, 04:22 PM

Doug: I had the same problem on my second (not first..it tested OK) tank. I had a small leak at the top of the baffle right in the middle of the tank. Here is what I did. I drilled out a few rivets either side of the leak. I wedged the skin up from the baffle using 16 ga hypodermic needles as wedges. I probably dulled the sharp edges of the needles on the Scotch Bright wheel to prevent gouging, but I don't recall exactly. I then injected tank sealant from a 5cc syringe through a 16 ga needle all along the raised skin-baffle gap, pulled out the wedging needles, and reset the rivets. Tested OK. I use the needles and syringes in my work so they were easy for me to obtain. Try looking in stores that sell supplies to farmers and horse owners; they do a lot of their own animal doctoring and buy syringes and needles. Don't use needles any smaller than 16 ga, although 18 ga might work if you thinned the sealant with MEK to make it flow better. Same deal with the syringes. The larger the syringes the harder it will be to force the sealant out. This method worked well for me. Good luck.

doug_rv7 · #4 11-29-2006, 10:55 AM

Thanks Stephen, I'll give that a try. I like that idea alot better than drilling hole(s) in the baffle.

Doug

Norman Stapelberg · #5 11-29-2006, 01:09 PM

Doug I had a leak on my first tank, on one of the ribs on the top, I used a vacuum pump to draw a vacuum to roughly 1/2 psi, using the manometer method. Put a drop or two of MEK on the leak and allow it to draw in, then placed some thinned down Pro-Seal on the area, allowed it to draw in. Once the blob was nearly gone I then released the vacuum, tested the tank two days later and leak is gone. Hope this will be of some use to someone.

Norman
Fuselage 5%

doug_rv7 · #6 01-18-2007, 06:13 AM

I went ahead and drilled a couple holes in the rear baffle to gain better access to the problem areas.

My question, has anyone else drilled access hole(s) in the rear baffle? And riveted access plates back on and not had any problem with leaks around the plates?

I'm thinking seriously about ordering the tank parts and rebuilding the entire tank again, taking this as a Tank Building 101 lesson.

Mel · #7 01-18-2007, 06:35 AM

That's the way we do all the baffles when removing slosh. We cut 4" holes in each bay, clean out the slosh, then rivet a cover plate on. Haven't heard of any leaks.

Jamie · #8 01-18-2007, 06:54 AM

Mel:

I've often wondered how folks do this. What tool do you use to cut a hole that big? It seems like a fly cutter wouldn't really work since you can't really get a tank under a drill press.

- Jamie

alpinelakespilot2000 · #9 01-18-2007, 11:14 AM

Quote:

Originally Posted by kentb

If the leak is not to large (mine just made a small stream of bubbles). Vans leak check documentation states to use locktite to seal it. It worked for me.
I can't remember the loctite type, but could look it up tomorrow if you need me to.

Kent

Green, self-wicking loctite is what Van's recommends in their tank test kit. It worked for me on the one leak I had (at a corner intersection between one of the outboard ribs and baffle). Hopefully it lasts a lifetime!!!

To help the loctite wick in, I used my shop vac at the fuel filler opening to just provide some light suction. It doesn't take much and you don't want to use full suction--might damage the tank.

Good luck.

Rick6a · #10 01-18-2007, 12:37 PM

As I assembled the fuel tanks recently, (thankfully, no leaks) it occurred to me during the process that Van could easily put together a tank access repair kit featuring 4 access covers which would be scaled down versions of the blank access plates now installed on the tanks of countless RV's. The repair kit would include a scaled down matching doubler ring same as is now installed only the builder would have to cut it in two for insertion, drill out, and installation inside the tank. Of course a full compliment of screws would be included in the repair kit. Van could sell one cover assembly for a sole problem area or up to four cover assemblies in a kit to provide access to each bay within the tank. Such a kit would be of particular interest to those builders who want to take on the job of removing slosh. All matched hole parts and fully interchangeable. Proseal not included.