16' aluminum Sylvan Sport runabout transom replacement?

[rtpassini]

So while painting the boat today, I noticed the rear wood in spots was soft. There is zero flex in the transom, but in the next year or two it should probably be done. What is involved with this on aluminum boats? It looks like the engine comes off, the corner metal end caps, then the metal strip that runs about the top of the transom. But what after that? Is it pretty involved?

https://dl.dropboxusercontent.com/u/28917583/2013-06-08 14.25.22.jpg

you can see some of the silicone and stuff that I scraped off.

 

[jbcurt00]

Re: 16' aluminum Sylvan Sport runabout transom replacement?

All that stuff on the transom wood looks to suffering from water intrusion... bubbling & etc:


Is this primer the "same" as zinc chromate?

 

[rtpassini]

Re: 16' aluminum Sylvan Sport runabout transom replacement?

its not though, I think what someone did, was glob some type of fiberglass or epoxy on it. The "bubbling" is uneven epoxy. that stuff is all rock hard, but I can peel some of it off.

 

[Watermann]

Re: 16' aluminum Sylvan Sport runabout transom replacement?

I hate to ask why someone would smear epoxy around like that in the first place unless there was a problem most people wouldn't bother. If you can, drill a core sample halfway into one of the soft spots and capture the shavings to examine. You can refill the hole either with a dowl and glue or epoxy putty. Unless it's rotten then refer to next paragraph.

It's not that tough of a job to replace the transom wood. You have most of the steps down for the removal except the splashwell has to come out and then the brace screws that are under it. Since she is a 1981 I would have to say it's time.

 

[jigngrub]

Re: 16' aluminum Sylvan Sport runabout transom replacement?

It sounds like it's time to change it out, even if it doesn't flex. Then you'll have a nice new transom that will last another 20+yrs. without a worry.

That may be epoxy on the transom under the paint, or it sounds more like someone used polyester resin without cloth or mat if it's easy to peel off.

Sealing your new transom wood with something will make it last considerably longer than not using anything and just leaving it bare.

 

[rtpassini]

Re: 16' aluminum Sylvan Sport runabout transom replacement?

the splashwell doesnt seem connected to it, which is why all that silicone is in there...are you sure it needs to be removed?

 

[jbcurt00]

Re: 16' aluminum Sylvan Sport runabout transom replacement?

the splashwell doesnt seem connected to it, which is why all that silicone is in there...are you sure it needs to be removed?

If the splash well is not connected to the transom, it probably should be. Which, as you mentioned, is why it's probably overloaded w/ Silly-cone. Most likely reason to remove the splashwell from the transom, is to replace the transom. Perhaps it was replaced previously.... But w/ what..... ???

Are you asking about removing the splashwell, or the transom ply in the quote above?

 

[jigngrub]

Re: 16' aluminum Sylvan Sport runabout transom replacement?

I agree with JBC above, the splashwell should be fastened to the transom for both structural integrity and to help seal it. Without the splashwell being fastened to the transom any sealant that is put between the 2 will fail. Sealing then fastening the splashwell to the transom will keep the joint between the 2 nice and tight and the sealnt can do it's job to seal out the water.

 

[lokonn]

Re: 16' aluminum Sylvan Sport runabout transom replacement?

I was able to get the transom out without removing the splashwell. That being said I ended up taking the splashwell out later and it sure made getting at things and working in that area much easier. It also made it easier to re-install transom, open area for rivets or nuts abd bolts. If I had to do it over again splashwell definitely would come out. IMHO.

 

[Watermann]

Re: 16' aluminum Sylvan Sport runabout transom replacement?

My splashwell has 8 screws into the transom and below that the brace has 10, #10 stainless bolts that go all the way through from the outter skin, through the transom to the brace and secured with nylocs. The screws holding the splashwell to the transom are on the underside. Someone thought putting sillycone in the seam would help keep the water in the well until it drains out the tubes rather than run into the bilge. You will have to start the process by removing the splashwell at the forward end of it first. Do you have a hatch opening where you can look inside the bilge area and see where all the screws are securing the splashwell and brace?

 

[rtpassini]

Re: 16' aluminum Sylvan Sport runabout transom replacement?

Got some pics up. Obviously all the top stuff I was talking about (end cap, rail, etc)
Do I need to unscrew all those big screws on the far left and right? Also, Do I need to worry about anything under the yellow line?
https://dl.dropboxusercontent.com/u/28917583/left.jpg
https://dl.dropboxusercontent.com/u/28917583/right.jpg

Then obviously all the screws here, along with the ones that go through the brace. Does the wood end at the yellow line? (sorry about the blur)
https://dl.dropboxusercontent.com/u/28917583/inside.jpg

 

[Watermann]

Re: 16' aluminum Sylvan Sport runabout transom replacement?

Anything that bolts through the wood transom obviously has to come out. I would have to guess that those big bolts are through the transom wood as well,, there should be some nuts on the inside that are easy to see. On the inside pic, the yellow line is on the brace it looks like to me and that is where the bottom of the transom rests. It doesn't look like yours has bolts that go through it to the outside.

 

[jigngrub]

Re: 16' aluminum Sylvan Sport runabout transom replacement?



That dark spot in the circle is water intrusion and rot, the spot on the other side will be at least twice as big.

It's easy to tell the previous owner didn't use marine sealant on the penetrations like he was supposed to (the cause).

It's also plain to see the PO didn't completely seal the transom like he should've, coat both sides and all the edges of your new transom wood before installation. Epoxy resin is the best sealer and I like to use 4 coats of it on any wood in my boat.

3M 5200 is what most people around here use to seal fastener penetrations through their hull, it's available at Home Depot and Lowes.

 

[rtpassini]

Re: 16' aluminum Sylvan Sport runabout transom replacement?

yeah, I noticed those dark spots, thankfully, those arent used to hold anything. its the metal loops on the other pics.

I think this will have to wait until the end of fishing season. I want to enjoy the boat for the first year I own it. Im just worried that its going to take me WAY too long and I will run into something that will hold me up from hitting the lakes.

 

[jigngrub]

Re: 16' aluminum Sylvan Sport runabout transom replacement?

yeah, I noticed those dark spots, thankfully, those arent used to hold anything. its the metal loops on the other pics.

Those U bolts (metal loops) are what most of us use to tie our boat down to the trailer, a ratchet strap from the loop to a loop on the trailer. It keeps the boat from bouncing around on the trailer while you're going down the road to or from the lake.

Do you have a strap that goes over the back of the boat to hold it on the trailer?

 

[rtpassini]

Re: 16' aluminum Sylvan Sport runabout transom replacement?

yeah i have tie downs, but they just attach onto the transom lip. I dont know, I thought they were weird, and will eventually swap them to normal ones.


On a side note. I figured its better to be safe than sorry. So I got the motor torn off and the metal strip off. the transom is pretty nasty. hopefully the rest of it goes somewhat smooth.

double side note. is it okay to "rest" the motor on the skeg? I still have the hoist holding most of the weight of the motor up. Its resting on a piece of 4" dense foam. Can the loop the hoist attach to hold this okay?

 

[jigngrub]

Re: 16' aluminum Sylvan Sport runabout transom replacement?

You'll be glad you fixed the transom after you're done.

Use ABX or BCX grade exterior plywood, don't use pressure treated plywood.

It would be better to hang the motor from something so the skeg wasn't touching anything, but probably won't hurt anything to have it like you described.

What kind of shape is your decking in? Any soft spots in it?

 

[rtpassini]

Re: 16' aluminum Sylvan Sport runabout transom replacement?

The PO just redid all the decking before I bought it. We'll see how long that lasts. I dont think he coated with anything. But if I get a couple years out of it, I'll be happy...hopefully. haha.


Finally got the transom out. mother of god did that suck. yanking it out was the worst part and took FOREVER. mostly because there were tons of screws put into the back then gooped over that I didnt see.

Question #1) Can I use that 5200 stuff to put in those holes in the back then paint over it?

Question #2) I didnt have access to epoxy resin. So I bought Polyester Resin to coat. will that be okay? Or I have been using this stuff for my crankbaits http://shop.hobbylobby.com/products/32-ounce-envirotex-lite-pour-on-finish-729723/ Can I use this stuff? I dont have enough to do the transom and was hoping to get it coated today. But I think my local store has it. and will probably only need 2 coats on the whole thing.

 

[jigngrub]

Re: 16' aluminum Sylvan Sport runabout transom replacement?

Take the polyester resin back unless you plan to fiberglass it with mat or fiberglass cloth. Polyester resin is very weak by itself and will crack and peel off in a short time.

You can seal your wood with paint, varnish, or exterior grade urethane if you can't get epoxy resin. Just make sure they're good exterior grades.

Any holes in the outside of the transom that you don't use can be skimmed over with JB Weld Marine or Loc-tite marine epoxy after you install the new transom wood. You can do the same to any holes on the inside if you want but you don't have to.

 

[Watermann]

Re: 16' aluminum Sylvan Sport runabout transom replacement?

#1 - No 5200 won't work, it's runny as heck and won't cure for a week. I had some extra holes through my transom aluminum as well that I used JB weld to fill and sanded them smooth. Rule # 1 don't over work the JB or it will never cure up hard. If you do it right, you'll never even know the holes were there after painting over them. I have no idea why there are 2 sets of stern eyes (metal loops) on your transom, the smaller outer ones are all you should need.

#2 - You don't have to use $80 a gallon epoxy on your new transom wood. I used a 3 step process to put the coating on mine. After the wood was laminated and the glue cured, I cut it to shape, dry fitted and when it fit good, I drilled all the holes I needed through the new wood. Then I took it out and started the coatings. 2 coats of oil base primer, 2 coats of oil base enamel and then 3 coats of Helmsman spar urethane. It looks like a liquid chocolate bar since I used a dark leather brown.

You will need to purchase some new drain tubes for your splashwell. If you get the metal ones, you will need to fabricate your own flange tool (instructions are here on the forum) but they also make plastic ones.