live well pump installation and pump questions

[seanymph85]

I just discovered that the live well pump an older Mayfair 2460 through hull/transom unit does not fit correctly on the inside of the aluminum boat I have. It may explain why someone had put so much silicone inside and outside of the boat in the area the "pipe" goes through the transom. In this case the hole for the pipe on the outside appears to be a similar or very close to the same position from the bottom as the drain plug.

When the pump is installed through the "pipe" hole in the transom, the side of the pump that faces the top of the transom is against the inside of the transom at the base of the pump but the opposite side facing the bottom of the boat is 1/8-1/4" away from the inside of the transom. So the base of the pump is not facing flat against the transom on both the side towards the bottom or the side facing the top of the boat.

In any case I either need to purchase a pump with a smaller imprint so the base where it in this case goes through the transom fits flat or tight against the transom all the way around thus helping to form a better seal assuming a seal is on the inside of the transom where the pump is as well as on the outside of the boat. The hole size for the pipe is very close or precisely the size needed as the hole itself fits fairly tight around the pipe all of the way around it.

I am trying to avoid having to have the hole moved to accommodate a good fit on the live well pump. Again short of finding a pump with a small imprint compared to this one I would need to somehow plumb the existing pump with and slight offset to move the largest diameter on the pump further away from the bottom and thus hopefully allowing the pipe on the inside of the transom to be sealed better.

The pump is out now so I could provide a picture showing the exisiting hole location for the pipe where it goes through the transom or provide some dimensions of existing pump if that would help. Sorry I know this post is long but tried to describe the situation as best I could to hopefully better enable suggestions on pumps or plumbing changes that could be made

 

[GT1000000]

Explanations help, but pictures, as you know are worth a thousand words, sometimes more...
Get some pictures posted showing what was/is there and we'll get something worked out for you...
Silicone really has no place in sealing openings below the water line...a much better product to use is a high quality, below the water line sealant, such as 3m 5200 or an equivalent...

 

[Watermann]

The aerator pumps come with 2 plastic nuts and a long shaft that goes through the hull. What should happen is you spin one nut all the way on the shaft, fit the pump and move the inside nut up to the transom. Next using 5200 not silly cone put a bead around the hole inside and out, put outer nut on and spin it down and tighten, then cut off the excess pipe shaft... done.

Sounds like that wasn't how the PO put the pump in your SN.

 

[Outsider]

Sounds as if 1) the hole is not square with the transom, or 2) the transom isn't flat. You have to solve that first, then re-install with a decent sealer rated for below waterline use. When (not if) the pump needs to come out, you (or the next guy) will be grateful you didn't use an adhesive ...

 

[glenn property of pam]

sometimes a generic pump just wont work on a hole thats been cut. Sometimes you just have to get inventive. No one said that the pump has to be mounted to the transom. You could mount a thru hull fitting (normally used for live well drains) then a small piece of pipe to the pump. some pumps come with kits that include all sorts of fittings, clamps and pipe to help you make something that works

 

[jigngrub]

Attwood pumps are fairly universal and easy to install.

 

[seanymph85]

No Title

I took all of the comments into consideration and they gave me some ideas to see if I could adapt this unit to fit properly. I have attached some pictures to illustrate the situation. You will note the picture of the pump with the nut that was on the outside of unit was threaded on and the whole pump was held in place as described in the picture the inside flat of the nut would indeed fit flat against the transom without the widest area of the pump in the middle hitting the inside bottom of the boat.

So now I have a couple of questions. A: Would it be acceptable to put this nut on the inside as described and if so I would need to come up with another nut to tighten down the whole unit for the outside. Any suggestions on obtaining a nut I could use on the outside or to replace this one on the inside?

B: When these units are installed sometime they come with seals. This one had a flat rubber type washer on the inside and a different type rubber grommet that was partly tore up on the outside. So does anyone think it is acceptable to not use the seals if a quality adhesive sealant is used? If so I have a new tube of 3M 4000 UV adhesive sealant I could use if it would be acceptable for this purpose. Thought it may or may not enable the pump to be removed or replaced if needed as someone suggested considering when choosing a sealant or adhesive. On this boat the hole fits very closely around the inlet pipe.

Also I have the rivets to replace the missing ones I took out. Some were sticking out slightly as I believe someone had tried to force fit the aerator at some point and pounded on the bottom inside of the boat causing a slight curvature you will see in a couple of the pictures. I will be cleaning the appropriate areas better before applying any sealant or replacing any rivets.

 

[seanymph85]

Also I was considering an Attwood Tsunami 800gph pump as it has a smaller profile than this one. Assuming I could not properly fit this unit.

 

[jigngrub]

I'd buy a new pump that fit better. Livewell pumps aren't that long lived, the best I can get out of one is 6 or 7 yrs. and they aren't that expensive.

 

[glenn property of pam]

wally world attwood live well recirclualing kit about 20-25 bucks comes with nuts screen and pump. I bought the kits as the screens can be 10 bucks on there own and theres enoght parts to make something that will work.

 

[seanymph85]

Thanks for the input. I do have no idea how long this pump has been on there. I know they don't mfg under the Mayfair name anymore so that isn't good. I'll check Wal-Mart and online for another pump and or pump kit with the extras like screen etc. The live well is already plumbed but it won't hurt to have the extra parts in case something wears out or breaks. Thanks for the suggestions on this.

 

[GT1000000]

Good thing about the Attwood aerator pump is the threaded intake has a built in "washer" that can be sealed directly against the inside of the hull, the plastic nut is then placed on the outer skin of the hull with sealant to form a water tight seal and there should be enough thread left on the intake to attach an intake screen...

I have mine set up a bit differently to allow me to change the pump motor while in the water, should it fail, but you can get a pretty good idea of what it looks like along with a shot of the intake screen...

 

[Watermann]

I too suggest using a new pump, they are not expensive and your old one won't have enough pipe to secure it on the outside and put a screen on too since the guy did such a bang up job on the install you're pretty much stuck getting a new pump from what I see.

 

[seanymph85]

Thanks for the tips and great idea about making the pump setup so you can change on the water if needed. The pictures are real helpful. Attwood T500 is what I am leaning more towards now but my concern with theirs is they suggest their polyurethane sealant which is fairly expensive and harder to find than some others. I have a new tube of 3M 4000 UV adhesive sealant rated for above or below water line but do not know if it is safe to use it on the pump inlet tube. 3M refers to it as being a
[FONT=&quot]polyether base.

Oh yea, did GT1000000 use sealant on the inside where the washer was as well and do you think it would hurt to use both a plastic nut and the washer on the inside as well as the nut on the outside if needed to adjust the pump for clearance near the bottom of the boat? Given the smaller profile of this one than the one I had I doubt I would need to do that but asking just in case. Also I am ordering one of those screens as well.[/FONT]

3M has great products but they won't commit to one that is tested as safe to use on this application or for a live well aerator. I assume some sealants might eat into some plastics so this leaves me overly concerned about what will do a good job, can be removed if required and is safe to use on the plastics in these aerator inlet tubes. Any suggestions given your experiences with this is appreciated. Also I have to re-install the transducer and it would be great if I could use the same sealant around the bolt holes on that as well as the seal on that was old and may be of little to no value..

 

[Rickmerrill]

No experience here but from reading up on polyether sealants it looks like they are low in VOC's which is all the rage now. Looks like a good fit. If you're worried about it eating the plastic see if you can find a safe spot to put a little on to see if there is any reaction. Sometimes the problem is that the sealant won't adhere to the plastic but if Atwood is recommending a polyurethane I think your good to go. 3m says sticks to most plastics but of course they don't say what it likes to eat. Do you have decent enough access to the pump so that it wouldn't be that big a deal if it did fail? I wonder in this case if there just trying to make a little money on "their" sealant.

 

[GT1000000]

Yes sir, I used 3M 5200...but you could use most any quality sealant that is rated for below the water line use as added insurance against any leakage...
I slathered on a coat on the threads and some on the inside of the hole before pushing it through, screwed on the nut and began the tedious task of wiping away the excess that spooged out...using either mineral spirits, acetone or lacquer thinner...can't exactly remember which one, as a solvent and used paper towels and as soon as they became a bit messy I would get a fresh one...
I really wouldn't worry too much about most sealants reacting with the plastic on the pump since these seem to made of similar material as PVC pipes...and only strong solvent based glues will have much effect on them...
And yes, if you want to adjust the height of it, you certainly can use another nut on the inside...the one caveat is that I think they only come with one nut...which in my first installation, I actually left long on the outside of the hull and when I figured out how far I needed it to still be able to attach a screw on strainer, I just cut the excess off...
Keep in mind that type of installation will NOT allow you to change the pump in the water, as removal of the pump motor will be like opening a huge hole in the hull...which is why I decided to install it the way I did in the pics above, with a shut off valve...

 

[Woodonglass]

Hmmm, so since you got that shut off valve, does that mean I can quit saving all my used wine bottle corks!!! You don't need em to stop up your live well holes???:faint2:

 

[seanymph85]

I realize that without adding the piping to have a shut off valve I would not be able to remove the pump and change it while in the water and will consider this option for installation when I receive the pump I will be ordering. I can likely purchase needed plastic fittings locally.

Given the comments above about not worrying about the sealant eating the plastic for the reasons mentioned above, I will just go ahead and try using the 3M 4000 UV sealant since I have a full unused tube on hand. If the pipe does fail later on due to sealant attacking plastic I can always replace the inlet tube and reinstall with something else.

The 3M 4000 UV is above or below water line, had high bonding strength to metal and is considered removable which if there was ever failure would make it easier to remove and repair as mentioned above.

 

[GT1000000]

Hmmm, so since you got that shut off valve, does that mean I can quit saving all my used wine bottle corks!!! You don't need em to stop up your live well holes???:faint2:

Noooooo, don't throw those corks away! They make great inexpensive, [read free], bobbers for blue gill fishin and plugs for re-bluing gun barrels...:watermelon:

 

[seanymph85]

GT1000000, were those plastic fittings you used a standard size that would fit the threads on the pump inlet tube? It appears you used 2 fittings that were glued in on the one end of the fitting going into the shut off valve and threaded onto the inlet tube on the other end. Is that the case? If so I can only assume with those fittings and the shut off valve you used did not reduce the inlet flow of water sufficient to impede flow of water to the pump. It would seem the inlet with the valve and adapters might be reduced below a 3/4" inlet size.

I am just clarifying as my Attwood T500 Tsunami pump should arrive anytime and I was considering a similar install arrangement with the valve and wanted to make certain I did not get the wrong parts that would reduce inlet diameter feeding the pump.