Transom plate reseal

[chris1200]

Thank you! No incentive to fill the inside surfaces? In the sense as making the same as you did but putting extra in the surfaces that are not covered? Or would that then be too much material and end up being counter productive?

In my opinion thats enough for a perfect seal and it will still squeeze out without creating a big mess

[ecarca]

In my opinion thats enough for a perfect seal and it will still squeeze out without creating a big mess

Got it, I was thinking of something like this, either lines like in my (very) basic drawing, or just a thin layer there where you have these red marks I made. In any case, as long as it doesn't try to sink anymore, I'll be fine

[K447]

… reason not to fill it with silicone … to obtain that hard … mating surface? ...

The idea is to extend the width of the cast aluminum area across the casting void with the epoxy fill. The epoxy will self-cure throughout the depth of the void. This provides a solid surface for the thin layer of sealant to grip.

Sealant normally cures by release of the solvents. Trapped in a deep metal cavity like those casting voids, the sealant will not cure.

[ecarca]

Sealant normally cures by release of the solvents. Trapped in a deep metal cavity like those casting voids, the sealant will not cure.

Crystal clear, thanks!

Another question: is it better to reinstall the rest of the jet assembly after 24h (if using 4200) so that the transom plate sealant has had time to cure or is it ok to reinstall everything right away? The service manual doesn't indicate waiting is needed, just curious.

[K447]

… I was thinking of something like this, either lines like in my (very) basic drawing, or just a thin layer there where you have these red marks I made. …

There will be a lot of sideways ‘squeeze’ of the sealant when the transom plate is put into place and the stud nuts are tightened to clamp the plate to the hull.

The sealant is not there to glue the transom plate to the hull. The studs hold the plate in place. The sealant so there to fill the small gaps between the ‘flat’ transom plate and the ‘flat’ hull surface, neither of which is totally ‘flat’. In the provided grooves the sealant will be the full depth of the groove, once the plate is tightened in place.

Everywhere else the resulting sealant thickness will be quite thin, almost nothing where the high spots contact and slightly thicker sealant film where small gaps and hollows occur.

If you review the photo I posted earlier you can see some areas where the white factory sealant was fully squeezed out and other places where a less thin layer of white coated the red hull.

Adding even more sealant to the areas you have marked in red will increase the amount of sealant that will have to be squeezed out, making a bigger mess to be wiped up around all the edges. And it will not improve the sealing result.

Enough sealant, applied in the right places, is enough sealant. More sealant is not better, just messier.

[ecarca]

Thanks for the detailed explanation, understood.

[K447]

… reinstall the rest of the jet assembly after 24h (if using 4200) so that the transom plate sealant has had time to cure or is it ok to reinstall everything right away?

The service manual doesn't indicate waiting is needed ...

I would wait a couple of days with just the transom plate installed, if you can.

What another member posted was to ‘snug’ the transom bolts to hold it in place with the wet sealant. Making sure the plate is exactly correctly positioned against the molded stops on the hull. And the curved top of the hull water tunnel aligns with the transom plate top curve.

I have sometimes supported the transom plate in position with some wood or a floor jack to keep it exactly in place.

Let the sealant cure for a couple of days, then torque the stud nuts for the transom plate to the full tightness spec. This ‘further compresses’ the cured sealant, potentially providing a tighter seal between the plate and the hull.

I typically would wipe away the squeeze out sealant around the edges while it is still soft. Use minimal solvent as you don’t want it to seep into the joint. Just clean up the excess so it looks tidy.

I do pay particular attention to the small gap and sealing between the pump tunnel top curve and the transom plate. That should be a perfect transition with just enough sealant to fill the gap and not present a lip, step or groove to the passing water flow. Just a smooth water flow into the jet pump.

Putting the entire jet pump back together with the sealant still wet is not a bad thing, and I have certainly done it that way. I just prefer to not have the weight of the jet pump hangin on the transom plate before the sealant has had time to cure. And it makes it easier to verify the plate has not slipped out of position when the jet pump is not mounted.

It can take more than 24 hours for the sealant to cure. Remember it cures as the solvents escape. The farther the ‘deepest’ solvents have to travel through the compound itself to reach outside air the longer it can take for the full cure to complete.

[ecarca]

Thank you

[ecarca]

I don't think it was ever removed since the ski was delivered in late 2012. As you know in my case it was not remaking factory's bad job but addressing an issue. In any case, I guess it would be good practice to reseal it after say 6/7 years, or every 200h or something like that (I have about 250h).