Need to level out around my transom cutouts

[US1Fountain]

I need to fill in the area on my transom where the gimble assemblies mount. At the top and bottom of the cutout, the gel has been worn down enough to not have a flat surface to mount the gimble assemblies to. I replaced the transom wood do to rot and it looks like the assemblies sucked into the gel. Still shiney gel, not dull from moving around. Just as if the wood was soft and the gimble units where pulled in. Not a huge amount, approx 1/16" or so at top and bottom. The middle is fine and flush when checked across wises, but is high when checked up/down within the gimble housing surface area, which is giving me a rocking on that point. I tried sanding the center down some and have a ways to go to get it flat, but I think the right way is to level the top and bottom back out. I'm right at 2" thick, so no room to get carried away sanding the center down.

What is the process for doing this?
I believe need to sand the gel off around the cutout down to bare glass, and add filler and sand flat, but not sure on what type of filler to use. I have some Cabisol from US Composites and some West System high density left over. Going to use Vinlyester resin as that's what I have used and am comfortable with it.

I see fillers that are easier to sand, but not sure about the compression charactristics of them for this application, plus if I can use the Cabisol, rather use it up vs buy more filler and just work harder at sanding. The area needing leveled out is just within the mounting area. Outside that it is flat.

Thanks

 

[jeffswav]

Can you take a few pics of the area?

 

[Offshore Ginger]

General rule of thumb in your case is...... if to high sand , and if to low fill , personally i think that you just need to work that area a little more other then sanding down to bare glass and start over because obviously that area is to high and if you need to fill i recomend getting p 77 fairing compound which is good above and below the waterline and can be used on Poly /Vinyl / and Epoxy which is a great option for the pure fact that not all fillers are designed for epoxy and this product is very easy to sand and would work fine on a transom............................ http://www.adtechplastics.com/c-31-faring-materials.aspx :seeya:

 

[US1Fountain]

1st (top) and 2nd (bottom)pic shows the wear when a straight edge is ran top to bottom, over the housing surface, thru the middle, so the high spots don't show up. If I where to place a straight edge confined within the housing surface only, it's pretty flat, (within Merc specs) other than at the 'ears'.

3rd pic is just a shot

the 4th and 5th pics show how much the 'ears' effect the straightness. 4th pic is with square held tight against the bottom of the housing surface and going across the 'ears'. 5th pic shows how much the high ears effect the gap at teh top. A small amount of too much height really effects the gap.

I have no problem if the housing surface could be flat and be sunk in, which could simply be achieved by sanding the high ears down. I estitmate a good 1/16" would need to be removed to get there. By doing so, I wouldn't have to gel the repair area since it will be painted with an epoxy barrier coating, then anti fouling paint. Have read were a lot of high dollar yachts have no gel coat below the water line to avoid blistering issues. That's good enough for me!

Artie, I'm not quite following you, are saying you would just sand the high down, or fill the low, or both and meet in the middle? Can I use the US Composites Cabasol as my filler if I need to go that route? I assume it will just require more effort to sand? I've built up a nice selection of stuff that I've used in this transom replacement that will just get tossed when done, so if posssible to use what I already have, even better.
Thanks

 

[gcarter]

Sort of like removing hooks and other general uneveness from the bottom.

 

[Offshore Ginger]

US 1 Fountain , i see that you have a hump in that area and either way it will have to come down and from the looks of things you most likely will have to go into the glass because your build up just might be to high and to tell you the truth i would take my time and try to sand the high spot out using a hog in that area or file board with guide coat and if you have to fill , yes by all means use whatever possible that you might have leftover if you fill the need but a good filler / faring compoung is much faster and sands twice as easy . I have to say that in your pics if you look at the (layup) on the cutout and l@@k at where you did your repair ( layup ) it shows the high spot having twice the beef .

 

[jeffswav]

Wow, pretty wavy, looks like you are going to have to fill and refinish the back. Mine was wavy also it took a lot of work to get it perfect.

 

[DAREDEVIL]

It actually looks like the gel is very thick on the center of the transom,,,straight edge and sand paper will go a long way !!!!!!!!:cheers2:

 

[US1Fountain]

I'll look into sanding it. Truth be known, I can sand great in 1 direction, but trying to get both directions flat, screw me up. Heck, I only know what side of the paper goes against the hull because the writing is on the back side.
The sunk in areas at the top and bottom kinda have me thrown though. I guess as long as the whole surface where the assembly mounts in is on the same plain and flat, it's ok. How far under 2" will still work and be safe?
Or is Merc thinking 1/4" under is trouble, so they spec out 2" thinking some will always come up short?

Thanks

 

[US1Fountain]

US 1 Fountain , i see that you have a hump in that area and either way it will have to come down and from the looks of things you most likely will have to go into the glass ......

OG, if I end up into the glass, do I have to regel it? As mentioned before, I'm going to be overcoating it with epoxy barrier, then antifouling paint, so I believe gel is not required underneath. Looking for some reassurance there.
Thanks!

 

[Offshore Ginger]

look in your box PM.............Artie

 

[jeffswav]

Take a look at the pictures of how I did mine, it was a lot of work. Do you have a DA and a long in-line sander?

 

[US1Fountain]

I have access to the sanders. Will be talking with OG for some guidance so hopefully I can go forward. This will be putting me at a screaching hault after this weekend till I know what to do.

 

[US1Fountain]

It actually looks like the gel is very thick on the center of the transom,,,straight edge and sand paper will go a long way !!!!!!!!:cheers2:

If you look closer, that's paint on the edge, not thick gel.

 

[DAREDEVIL]

If you look closer, that's paint on the edge, not thick gel.

Where are u located ?????

 

[US1Fountain]

Indiana

You up for a LONG road trip?

 

[DAREDEVIL]

Indiana

You up for a LONG road trip?

Not yet..lol

But my buddy in Indianapolis could help for sure !!!!!

Or u could bring the boat down here ?????????

 

[US1Fountain]

I have considered trying to find someone to come take a peek at it, just haven't got to that point yet. Indy is just an hr N of me. Have a buddy that owns a dealership there, if all else fails, might have see if his glass guy works on the side. I have no trailer for it, so hauling it around isn't an option.

 

[Geronimo36]

sand the high spots but try not to get outside of the transom outline area so it doesn't become a huge re-finishing project. If that happens you'll find yourself refinishing the whole transom

Almost all old boats that I've taken transom assemblies off of kinda look like that.. A lot of it comes from people overtightening the backing plates over the years... Dry fit the transom assembly and if it fits flat and can make a good seal let it fly....

I'm sure the perfectionist's will think otherwise but it's more common what your seeing than you think..

 

[US1Fountain]

That's what I'm going to do, start off with just working within the transom unit surface itself and ignore outside that area. I want to avoid gel work if at all possible. This is going on a cruiser that will live in teh water, so perfect is not a requirement here. Had a very nice conversation with OG this afternnon and he said just as you.

Thanks