Black Tank Seal

Bogie · 03-26-2018, 01:39 PM

So I noticed a couple of drips of antifreeze coming from the seal on the black tank. I assume I am in for some fun maintenance. Luckily I think that the tank was mostly drained before I bought the RV so hopefully it won't be too bad.

So what do I need to do to fix this myself, or should I take it in somewhere. Seems like it should be something I can do I am relatively handy.

**revjeffrey** · 03-26-2018, 01:46 PM

Quote:

Originally Posted by Bogie

So I noticed a couple of drips of antifreeze coming from the seal on the black tank. I assume I am in for some fun maintenance. Luckily I think that the tank was mostly drained before I bought the RV so hopefully it won't be too bad.

So what do I need to do to fix this myself, or should I take it in somewhere. Seems like it should be something I can do I am relatively handy.

I know this sounds crazy but. I would clean it really well with rubbing alcohol and use that Flex Seal tape it's about 4 or 6 inches wide.
I used it as a temporary fix on my pool skimmer and somehow to my astonishment it's sort of welded on to the plastic I will never be able to get it off. You should test a piece somewhere the longer you leave it on the better it adheres. I am also going to use it for my sensor wires on the tanks will never come off and be sealed once and for all.

Bogie · 03-26-2018, 01:51 PM

That's not a bad idea. I am assuming if I loosen that clamp though to slide the tape under there I could loosen more things up... but it doesn't seem that clamp is actually doing anything.

JamieGeek · 03-26-2018, 02:47 PM

I'm not so sure the hose clamp is supposed to be there to begin with. Its all plastic fittings, there isn't any rubber hoses that would require a clamp.

2nd: Is that your black or grey tank? I ask because the exit pipe at the left of the images looks like the smaller pipe for a grey tank.

Bogie · 03-26-2018, 03:01 PM

For some reason I thought that was the black tank, but it is right under the shower and confirmed the valve is grey. So only grey tank, I am less worried now lol. Still need to fix it, but I will try the flex tape first and probably take off that clamp to see what the deal is.

Travelin' Texans · 03-26-2018, 03:48 PM

I'd remove the clamp, as it appears to be leaking at the clamp, clean it up very well & try to determine what the clamp is covering before using the Flex tape.

Bob Denman · 03-26-2018, 04:14 PM

Good luck! Try to keep yourself "upstream", during the sealing process...

Bogie · 03-26-2018, 05:37 PM

Alright, went out and cleaned it up. Took off that clamp, it was literally clamping nothing. If I had to guess they probably had it around the seal at one time.

Cleaned up there appears to be some sort of caulking material that was put on around where the valve connects to the tank and that looks like where it leaked out from. Must be a slow leak, but a leak nonetheless.

Is there some sort of special caulk they use, or should I just try the flex tape? Flex tape seems like the easiest solution but not sure how well it will seal since there is caulk all around that seam.

Bogie · 03-26-2018, 05:41 PM

What's funny is that you can see where the clamp was cranked on around the plastic as it left indentations, but I am not sure what exactly they were trying to clamp.

Bogie · 03-26-2018, 06:05 PM

Might be overkill but I was thinking getting some JB Weld for plastic and then putting a layer of flex tape over that. Looks like the bottom part either wore out from time and road debris damage, or just flexing from travel. I gave a good tug on all the parts and nothing really moved.

**16ACE27** · 03-26-2018, 06:13 PM

When you go down to HomeDepot to get the FlexSeal tape get a small tube of 3M 5200 Adhesive Sealer. Use the 5200 first to glue the joint and add some strength to it, then use the tape. In the marine world we always say use 5200 if you never want to take it apart.

Bogie · 03-26-2018, 06:18 PM

Quote:

Originally Posted by Tfryman

When you go down to HomeDepot to get the FlexSeal tape get a small tube of 3M 5200 Adhesive Sealer. Use the 5200 first to glue the joint and add some strength to it, then use the tape. In the marine world we always say use 5200 if you never want to take it apart.

Thanks. I will take a look for that!

Bogie · 03-26-2018, 07:03 PM

My best guess from looking at the parts: It looks like something was probably out of alignment somewhere, either during construction or a later repair, so rather than fixing it correctly the tank reducer is joined by some sort of rubberized sealant that has probably just been worn away over time.

Bogie · 03-27-2018, 03:07 AM

My guess was wrong.

Lot's of reading later, I have a pretty good idea how the whole tank drain system goes together. Definitely not engineered very well, but I suppose it works. Going to go with trying to get some silicon on their to seal it up, as least temporarily.

That hose clamp actually does serve a purpose. Apparently, the tank and the eccentric reducer are two different plastics, so they can't be glued together. Since they don't fit precisely and you don't want anything with an "edge" that could catch material and build up they put in some sort of sealant and then clamp it on.

Fun!

So, for now, I'll do the temporary fix. It doesn't look extremely expensive to order the parts to completely repair it, but I haven't found out what the sealant they use for the reducer and the tank is.

**16ACE27** · 03-27-2018, 10:20 AM

Forget the silicon and get the 5200 I recommended.

Bogie · 03-27-2018, 04:00 PM

Quote:

Originally Posted by Tfryman

Forget the silicon and get the 5200 I recommended.

Permanent scares me.

Means a lot of extra work if I have to pull apart the plumbing in the future.

Bob Denman · 03-27-2018, 04:17 PM

Don't think of it as "permanent". Keep reminding yourself that it'll only last a day longer than you will...

Bogie · 03-27-2018, 04:24 PM

Quote:

Originally Posted by Bob Denman

Don't think of it as "permanent". Keep reminding yourself that it'll only last a day longer than you will...

Bob Denman · 03-27-2018, 04:33 PM

Thank you... I'm here all week: tip your waiter, and try the veal!

**16ACE27** · 03-27-2018, 05:50 PM

Quote:

Originally Posted by Bogie

Permanent scares me.

Means a lot of extra work if I have to pull apart the plumbing in the future.

Like you would want to pull apart the plumbing in the future.

Permanent in this case means you will have to break out the razor knife, not that it's welded together.

If you put silicon on there don't ever expect anything else to stick to it.

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