86 204c Transom Project

[sfc2113]

I am currently pulling out the wood core of my 86 204 transom, There is a layer of fiberglass mat between the layers of 3/4"plywwod I am finding in the rotted wood.

Is this a grady contruction? should I plan to install a layer of glass mat in the replacement material?

 

[richie rich]

It is the way Grady did it....but it not required....just use thickened epoxy in between each layer of wood.....you can add an extra layer or two on the outside/inner skin to make up the thickness difference and it may actually be stronger.

 

[Grog]

If you're going to use epoxy you can pass on it but if you use resin use the mat. Cost wise it isn't going to make much of a difference. How are the stringers? Going from the inside or outside?

 

[sfc2113]

thanks, I am doing this from the outside same as cdwood did. The stringers are good had them checked by surveyor 2 yrs ago.Was told about the transom then and he said I would get another season or 2 out out of it but after that I am taking a huge risk. HE WAS RIGHT. if a surveyor tells anyone here the same thing he told me, get to work on it right away. I can see now it was foolish of me not to. I was probably one or 2 more offsore trips from disaster. Will try to get my pics and vids posted in another thread soon as I progress more.

 

[richie rich]

Going from the outside?? Make sure you leave as much material or original outer skin as possible to bond the new glass to....otherwise you'll have to wrap it around the gunwales and bottom to get a good surface bond and then you'll need to fair it....that's alot of extra work

 

[sfc2113]

I can see where doing it from the inside whould be the preffered way, But, I am into this now. And, beleive me after doing the work I have done so far, my back would not be able to handle the bending and kneeling, ripping out the wood from the inside.I would probably be laid out in bed in agony now taking a sick day from work.... lol. I used the measurements for a 12/1 belvel from the west systems fiberglass repair manual, so hoping that 6in span will be enough to replace the skin to get a solid bond

Here is my progress:

Oh one other note: The sea cast or purable idea I had.... yea, now I see the light. I would not reccomend to anyone to do that.

 

[richie rich]

6 inches of area is pretty good....I would grind the motor well area a little and wrap the new outer skin over and around the core to the inside as you can see there...you'll need to do that anyway to secure the joint between the new and existing glass in the m-well....demo work looks good....grinding the glass is always fun......NOT! Get that nasty part done before it gets too hot....it's brutal getting covered in glass dust in high heat and humidity.

 

[cdwood]

Paul, richie's right about tabbing around the motorwell edges, gonna need a solid corner around there. How thick was the skin when it came off?..... yeah I know it's not that uniform.

 

[sfc2113]

hmmm, tabbing, thats new term for me, I guess I will have to save that part for when you come over to help me glass it in :wink:

 

[cdwood]

In that case it means grinding down the edges and building the outside corner back up for strength.

Maybe tabbing wasn't quite the right term.

 

[richie rich]

close enough...you get the gist of it..just another area of the perimeter to secure to existing glass.....although tabbing is required as well.....thats the use of a couple layers of narrow width glass tape to adhere to all the corners/border first, then glass over with full width sheets.....like painting a wall in the house..cut in first with a brush, then roll the main area....tabbing adds alot of strength to the new part. Take a look at Vero Wings rebuild...it shows it in his pics....he just did his from the inside

 

[sfc2113]

ah ,ok yea I see now. The stuff is real thin on top section around the MW, some of the inner skin is not even connected to the MW edges but it gets thicker in the center, then gets thin again near the bottom. very un-uniform. So, you saying reinfoce the edges with fg cloth tape and then build up the inner skin a bit with cloth and resin to stiffen it up uniform.

 

[richie rich]

That, and when you do your outer skins and cover the 3 sides (the 6 inch area you left) also come over the top and sides of the motor well to tie all 4 sides of the transom together.

Here's a link to VW's project...see how he tabbed the corners on page 2...then see how he wrapped over the top and sides of the new core to the outside on page 3....you should do that, but go to the inside to complete bonding the entire perimeter.

http://boatbuildercentral.com/howto/tra ... /index.php

 

[sfc2113]

Excellent suggestion, I see the light now. great stuff. Have printed out that link ,thanks. Keep the advice comming.

Got a long way to go with the demo work so I will update on my progress. Should be another couple weekends of removal yet. Any ideas how the get the wood out of the 3 inch area that is still sandwiched outside the cut line, for now I am using a small 1/2 wood chisel. Pain staking and slow but effective. :hmm

 

[richie rich]

air chisel and a 4 or 6 inch disc grinder...and get a good disc grinder....I killed a craftsman real early in its life...the bearing sits in a plastic housing and melted from the heat....bought a Makita and haven't had an issue yet.

 

[cdwood]

kudo's on the Makita. got the 41/2 in. before I started any of my projects. Kicked a$$ and still going strong.
I'd offer to lend it to you but your gonna need it for a while. something like this you really should have your own!!!

 

[sfc2113]

Thanks, will pick it up a makita on the way home from work.

 

[cdwood]

Paul, just write it off as part of the cost of the project, but when your done you still have an awesome tool. Besides your saving tons by doing this yourself.

 

[sfc2113]

Ok thanks guys, all the cool tools worked. I got a dewalt 4 1/2 in insted of the makita only because it was better deal, @ $59.00 and a 3yr protection plan.

After a couple of weeks here is where I am at. All the wood out. Except for some still stuck to the inside of the remaining 3in of outer skin. I can get that out with a drum sanding disk on a drill. Some of the upper skin on the port side around the fuel fill hose came apart during the skin removal, and the upper tabbing is still stuck on the inner skin as you can see. Should I need to reconstruct that? Does not seem like it had much to do with the strenth. Now for some glass work, I plan to tab up the sides of the skin to the motor well as they were not attached to begin with. Also, as you can see the lower engine mount holes are trashed :wow , will need cut out out and patch that area.

Have ordered the wood. will be delivered this Sat,,, :dance Now a question on west systems hardner. I plan to start getting this back togther starting Mid Apr, With the average temp in the 50's (possible 60's on some days) and at night could drop to 35. What hardner should I be using, I have 206 slow for my 105 resin, will I be risking anything using this hardner in these temps? I do plan on waiting till the daytime temps and surface temps are 55+ before I start applying any resin, but how will temp drops during the cure affect the resin. I do plan to allow a week of curing between layers. So I figure it will take me about 3 weeks complete the rebuild, then is fairing and gelcoat in mid May when the temps are in the 60's +

Total Labor hours so far from start to this point: 18.5

 

[cdwood]

A week between layers should give you plenty of cure time even in the cooler temps. One thing I used to do was to store my West products indoors overnite so they would be ready to go asap.
We talked about building up that inner skin.
Where you are right now looks exactly like mine did not too long ago.
The photobucket access working out for you?