Water Pump - need help identifying screws used to anchor the system

[Boudicca908]

Can anyone help me identify the TYPE and SIZE of screws to anchor the lines around the Water Pump?  I have found several of these are missing (see photos attached), and am loathe to take any out, because I'm not sure whether I can re-install them by hand OR whether they will stay in place, if mounted into the existing holes.  I'm on the road (not at home) and haven't been able to find a hardware where I can pull in with my trailer in tow to get help with this. 

I don't have power tools, so am limited to using the standard screwdrivers. 

Does anyone have suggestions or solutions:

- alternative mounting (screws of different size, addition of some kind of glue, or different system to hold them down)

- how to size screws (in general) without removing them 

Is this standard (another thing to add to the list for pre-trip maintenance)? 

I have inquired at OTT mothership (I discovered them missing right after my maintenance service). They have not been able to assist with identifying the screws used, nor suggesting methods to reinstall or what to use in place of original anchors.  EDIT: ** They did suggest that I could "try gorilla epoxy" to see if it would help (once I find the right size and type of screws to use, one would assume).**

 

Edited October 1 by Boudicca908
added info

[mossemi]

@Boudicca908

The man made mounting material or as I refer to as PVC, does not hold screws or threaded fasteners very well when using the same size fasteners as were original installed.  I would suggest removing one of the existing screws and then finding the same type of screw that is one size larger.  I think they are common pan head screws and installation and removal can be accomplished with a Phillips screwdriver.  Some type of adhesive may help, but anything like epoxy may make removal difficult.  So if you do use an adhesive, use it sparingly.  You can always add more the next time.  
 

Mossey

[Boudicca908]

3 hours ago, mossemi said:

I would suggest removing one of the existing screws and then finding the same type of screw that is one size larger.  I think they are common pan head screws and installation and removal can be accomplished with a Phillips screwdriver.  Some type of adhesive may help, but anything like epoxy may make removal difficult.  So if you do use an adhesive, use it sparingly.  You can always add more the next time.  

Thank you for this. I will go find some tomorrow and inquire about adhesive suitable for this project and materials. 

[Geronimo John]

On 10/1/2025 at 7:54 PM, Boudicca908 said:

Thank you for this. I will go find some tomorrow and inquire about adhesive suitable for this project and materials. 

Totally agree with Mossey.  As to a product to use with your next size screws I would consider is a small tube of silicon sealent/adheasive.

It will allow removal of your new Stainless Steel screws, yet help keep them in place.

Thanks for your post.  Frankly I have never really LOOKED at mine.  Will do shortly!

Geronimo John

Edited October 10 by Geronimo John

[Boudicca908]

FOLLOWUP:  I took a photograph of the side of the board where my equipment is mounted. I don't know what it is, but I wouldn't call this PVC; I would call it foam core. It's so soft on the inside that I can poke my fingernail into the side.   *haha -- I don't know why it's posting upsidedown; it doesn't appear that way on my computer until I insert it here*

I purchased both #8 and #10 x 5/8" screws yesterday.  I wandered through the hardware and pondered all the glues, epoxies, and wood fillers, but felt that I should begin with the medium locktite that is already in my kit.  I tried to post a video to demonstrate, but suffice to say: there is no purchase for any type of screw. It's useless.  **hints on video uploads?**

I installed only one of the screws, because I expect it to fall out tomorrow when I drive to my next destination.  I did not remove any screws; only 3 of the original 7 that I can see are still in place. I will update here after some towing, about whether this screw stays in place. 

QUESTIONS:

1) Does everyone have this same foam material as the base board for the mounting of your water pump equipment? Or is it possibly a substitute used during the 'short supply' years of Covid?  

2) Has anyone tried replacing this board? My conclusion is that I will have to replace the entire board (or ask OTT to do it) because there isn't enough flexibility in the design of the system to move the pieces around and use a new spot on the board for attachment. 

I'm interested in what others find.  Thanks for the help!

Edited October 3 by topgun2
added photo

[Boudicca908]

5 hours ago, Geronimo John said:

silicon sealent/adheasive

This is something that I didn't consider (and neither did the hardware guy). I don't have any in my kit, so will be looking next time I'm near a hardware store. 

[Rivernerd]

38 minutes ago, Boudicca908 said:

Does everyone have this same foam material as the base board for the mounting of your water pump equipment?

The rigid "foam" board is what we have in our Hull #1291 manufactured in October, 2022.  It may not be apparent in the photo below, but our mounting board is not solid PVC.  It has a "foamlike" feel to it, especially on the edge.  It feels to me like it is a cross between solid PVC board and foam insulation board.

That said, we have had no issues with screws loosening from that board, but we avoid driving on bad roads with our Oliver.

I second Mossemi's "one size up" and Geronimo John's silicone adhesive recommendations.  A "little dab'l do ya" on the screw threads.

[johnwen]

3 hours ago, Boudicca908 said:

Does everyone have this same foam material as the base board for the mounting of your water pump equipment? Or is it possibly a substitute used during the 'short supply' years of Covid?  

We have it...2022 Hull996.  Our accumulator mount screws pulled out and left craters where the screws were.  We tried VHB tape to no avail.  I'm also looking to replace that board and looks like everything attached to it will have to come off.  I haven't really studied the situation.  We will be back in SC this weekend for a few weeks so I'll tackle the problem soon.  We have hit some monster bumps and dips on the roads this year.  Our "Bessie" joined the 64,000 mile club last week so I expect a few issues like this will crop up...gives me something to do :)

Good luck,

John

[katanapilot]

This doesn’t answer your question directly, but may give you some food for thought.  When I did the full Victron electrical system upgrade, I wanted to also upgrade the mounting method of most of these components.  As you have found, sheet metal screws into PVC board isn’t exactly the most secure.  So for most of the components  I installed, I also used brass threaded inserts of various sizes - depending on the weight of the component and the mounting - vertical or horizontal.  It’s a little more work, but it’s a very secure mounting method if installed correctly. 
 

https://www.amazon.com/Z-Threaded-Insert-Internal-Threads/dp/B00207NF6W/ref=sr_1_8?dib=eyJ2IjoiMSJ9.DGW1I2sdUlWBQMbecRdN1iMmRcq6Ckucrt-5cHlTGY5RYWzcdmFoUG4qRk6LclmKYaxzhYX3lC7tfKsu8RDNblUeEkg54NBy50z3oBTFE5ZeP59dsYyB4WHq758aJz0K8CHMucPo9GtVKiC5c2rR4i4KRmqwaw1-nVPauSmq1tey0aUXEeRBoIQcNAFNdicNHu3sHwVWwfrgj5PemUXIGRHLK2gziE078GGFLwrPe74._T9JMhLIQjGnr1JN_QYoT8MS7rGJPVIZT_YbZ3oUNjc&dib_tag=se&keywords=threaded%2Binserts&qid=1759539352&refinements=p_n_material_browse%3A17548933011&rnid=17548926011&sr=8-8&th=1

[Boudicca908]

21 minutes ago, katanapilot said:

So for most of the components  I installed, I also used brass threaded inserts of various sizes

Did you install them into the existing foam core board? If so, did you use epoxy on the outside of the brass? 

[Boudicca908]

3 hours ago, johnwen said:

We tried VHB tape to no avail

I had to look this up — and seeing this product gave me an idea I might try… 

Has anyone tried using industrial grade velcro straps for securing these pipes? 

 

[katanapilot]

8 hours ago, Boudicca908 said:

Did you install them into the existing foam core board? If so, did you use epoxy on the outside of the brass? 

Yes, the inserts were installed in the factory board, but I also added several pieces of Azek PVC board that I had on hand.  No, I did not use epoxy on any of the inserts. 

[Geronimo John]

These fasteners rely on the strength and having thicknes of the mounting board.

 

I prefer to use Rivet Nuts (AKA RivNuts/Blind Flange Nuts).  They have the advantage of expanding on the far side of the connection as well as board strength for pullout.  I've found them to be quite strong when the surface being mount to is solid.  Would not work on "foam board", but for PVC and metal they are super... at least from my experience.  

Edited October 5 by Geronimo John

[katanapilot]

18 hours ago, Geronimo John said:

These fasteners rely on the strength and having thicknes of the mounting board.

 

I prefer to use Rivet Nuts (AKA RivNuts/Blind Flange Nuts).  They have the advantage of expanding on the far side of the connection as well as board strength for pullout.  I've found them to be quite strong when the surface being mount to is solid.  Would not work on "foam board", but for PVC and metal they are super... at least from my experience.  

I've used both of these type of nuts.  Airplane mechanics call rivnuts "the spawn of the devil" because they inevitably come loose and start to spin.  They are difficult to then either remove or squeeze again to try to tighten them up.  That being said, I've had a couple of airplanes where these are used (and yes, some have come loose). 

The benefit of the threaded type inserts is they can be installed in much more cramped spaces - like the bays of the Oliver.  The rivnuts (especially the large ones needed to mount the Victron Multiplus II) require a tool that is too large to fit into the bays.  

[jd1923]

4 hours ago, katanapilot said:

I've used both of these type of nuts.

Me too. Love the threaded inserts that @katanapilot suggested for use in wood and perhaps PVC and other synthetic boards, minimum 1/2" thick and the board has to be of a woody-like substance that will take the threads of the inserts without cracking.

Like the rivets that @Geronimo John suggested, for as he wrote, for thinner materials (where a threaded insert would not work). I used a different kind of rivet than the one pictured above (see link below).

When it comes to something as heavy as the Victron Multiplus II (64 lbs), it should not be mounted to a board with any kind of fastener, when the board is merely glued to a vertical surface. This is why I built a platform, for it to sit on, and then strapped the MP2 connected at the top with rivet nuts to the inner structural fiberglass that supports the bed platforms. I also did not purchase any long rivet tool. I used a longer bolt and extra nut to compress the rivet in place (see pics). These are the 1/4"-20 "Plus Nuts" I used and I also bought an M5 set for lighter needs.

https://www.amazon.com/dp/B0D4KBZG94?ref=fed_asin_title&th=1

Edited October 6 by jd1923