Prop strut backing plates
Moderators: BeaconMarineBob, Moderator, BeaconMarineDon
Prop strut backing plates
Hey gang.
I’m due to replace the soft (wooden) propstrut backing plates on the boat. Can anyone provide any insight or tips? What can I use as a wood replacement? Or stick with wood?
F32—on land.
I’m due to replace the soft (wooden) propstrut backing plates on the boat. Can anyone provide any insight or tips? What can I use as a wood replacement? Or stick with wood?
F32—on land.
- prowlersfish
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Re: Prop strut backing plates
I used oak myself .
Boating is good for the soul
77/78 TROJAN F36 Conv.
6BTA Cummins diesels
Life is to short for a ugly boat
77/78 TROJAN F36 Conv.
6BTA Cummins diesels
Life is to short for a ugly boat

- WayWeGo
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Re: Prop strut backing plates
Another option is G10 fiberglass sheets. A bit more expensive but won't ever rot.
1975 F-36 Convertible
Twin Chrysler 440's
Twin Chrysler 440's
Re: Prop strut backing plates
Did you remove the tanks in order to gain access? I think I have enough room if I remove the wooden aft fuel tank brace. And it looks like there is some sort of adhesive between hull and wood. I plan to 5200 the bolts and bottom of new backing plates.
- prowlersfish
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Re: Prop strut backing plates
I have a F36 so it would be different access .
Boating is good for the soul
77/78 TROJAN F36 Conv.
6BTA Cummins diesels
Life is to short for a ugly boat
77/78 TROJAN F36 Conv.
6BTA Cummins diesels
Life is to short for a ugly boat

- P-Dogg
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Re: Prop strut backing plates
I used 0.5 in fiberglass sheet from the Man's Toy Store -- mcmaster.com.
Took it to a granite countertop place n had them water jet cut to size. No risk to my health. Expensive, but didnt ruin any saw blades. Perfect edges too. Also had them do seacock backing plates and my underwater exhaust backing plates. Search tricab underwater exhaust 'n my user name for pics.
But I dont exactly have a reputation for cutting corners. That said, your wooden ones lasted how many years...?
Took it to a granite countertop place n had them water jet cut to size. No risk to my health. Expensive, but didnt ruin any saw blades. Perfect edges too. Also had them do seacock backing plates and my underwater exhaust backing plates. Search tricab underwater exhaust 'n my user name for pics.
But I dont exactly have a reputation for cutting corners. That said, your wooden ones lasted how many years...?
I needed a less expensive hobby, so I bought a boat!
Re: Prop strut backing plates
P-dogg—funny you mention it because my father said the same, and I have to completely agree and continually remind myself that the wooden ones have lasted this long; why change now?
Re: Prop strut backing plates
By the way, does anyone know the bolt sizes off hand? I’d like to source new hardware before I start taking things apart.
- P-Dogg
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Re: Prop strut backing plates
I threw that out there because I acknowledge that it might be OK for some folks, but that's just not how I roll though. I own my OCD.
The nicest thing ever said about me I wasn't supposed to hear. Was replacing the cable life line that was on the center third of the boat. Bow and stern already had pipe on the top. Made mine pipe all around.
Was on the hard and needed a hand. Hired the local mechanic's helper to, well, hold the end of the pipe. While working, I explained that I removed all the stanchions, drilled bigger thru holes in the deck, filled w epoxy, and redrilled. Also that I put large chamfer on top of hole to ensure ring of sealant even if bolt ended up rubbing hard against hole in deck when installed.
When he got back to the shop, I overheard him tell the mechanic "There's a guy you want to buy a boat from, not try to sell one to."
Almost brought a tear to my eye....
I needed a less expensive hobby, so I bought a boat!
- P-Dogg
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Re: Prop strut backing plates
And IIRC, diameter was 3/8". Length about 4", but you can guesstimate that. Hull might be 1/2" there. They are generally thinner than people think.
I needed a less expensive hobby, so I bought a boat!
- RWS
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Re: Prop strut backing plates
+100P-Dogg wrote: ↑Mon Mar 16, 2020 9:16 pmI threw that out there because I acknowledge that it might be OK for some folks, but that's just not how I roll though. I own my OCD.
The nicest thing ever said about me I wasn't supposed to hear. Was replacing the cable life line that was on the center third of the boat. Bow and stern already had pipe on the top. Made mine pipe all around.
Was on the hard and needed a hand. Hired the local mechanic's helper to, well, hold the end of the pipe. While working, I explained that I removed all the stanchions, drilled bigger thru holes in the deck, filled w epoxy, and redrilled. Also that I put large chamfer on top of hole to ensure ring of sealant even if bolt ended up rubbing hard against hole in deck when installed.
When he got back to the shop, I overheard him tell the mechanic "There's a guy you want to buy a boat from, not try to sell one to."
Almost brought a tear to my eye....
RWS
1983 10 Meter SOLD after 21 years of adventures
Yanmar diesels
Solid Glass Hull
Woodless Stringers
Full Hull Liner
Survived Andrew Cat 5,Eye of Charley Cat 4, & Irma Cat 2
Trojan International Website: http://trojanboat.com/
WEBSITE & SITELOCK TOTALLY SELF FUNDED
Yanmar diesels
Solid Glass Hull
Woodless Stringers
Full Hull Liner
Survived Andrew Cat 5,Eye of Charley Cat 4, & Irma Cat 2
Trojan International Website: http://trojanboat.com/
WEBSITE & SITELOCK TOTALLY SELF FUNDED
Re: Prop strut backing plates
Update for anyone needing to do the same on their F32, without removing the floor/tanks.
With the help of a friend and a Home Depot/lunch run, it took about 6hrs to replace both.
Things to note:
1/4 tank of fuel in both.
The aft freshwater tank in between fuel tanks must be removed.
In order to raise the tanks to gain access, I obviously removed tank straps. Removed aft wooden tank braces. I drilled 1/2” holes on each floor joist that were above the tanks, and inserted a 1/2”x10” carriage bolt. From there, I attached a ratchet strap end to each bolt and placed the strap under the tank (aft side). Crank away—the tank will raise like magic. There, you’ll have more than enough room to do what you need to do.
1 of 12 bolts came out in 1 piece.
Used 1 full-size tube of 5200
Sore back/hands/knees are currently setting in
With the help of a friend and a Home Depot/lunch run, it took about 6hrs to replace both.
Things to note:
1/4 tank of fuel in both.
The aft freshwater tank in between fuel tanks must be removed.
In order to raise the tanks to gain access, I obviously removed tank straps. Removed aft wooden tank braces. I drilled 1/2” holes on each floor joist that were above the tanks, and inserted a 1/2”x10” carriage bolt. From there, I attached a ratchet strap end to each bolt and placed the strap under the tank (aft side). Crank away—the tank will raise like magic. There, you’ll have more than enough room to do what you need to do.
1 of 12 bolts came out in 1 piece.
Used 1 full-size tube of 5200
Sore back/hands/knees are currently setting in
Re: Prop strut backing plates







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- WayWeGo
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Re: Prop strut backing plates
Well done! You were moving right along to get that done in 6 hours.
And thanks for posting the results here. If we keep doing that, this site will continue to be extremely valuable for those who have to do the same job later.
And thanks for posting the results here. If we keep doing that, this site will continue to be extremely valuable for those who have to do the same job later.
1975 F-36 Convertible
Twin Chrysler 440's
Twin Chrysler 440's
Re: Prop strut backing plates
Use white oak and it will last as long as the old white oak your replacing. There is a big diffence between red and ahite oak as far as rot is concerned. White oak is superior to red oak.
1976 Trojan F-32 Sedan Home Port is Catawba Island live in Wadsworth Ohio