My idea for temporary stringer repair

rickryder

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Re: My idea for temporary stringer repair

I guess you can call it the engine mount block ;)... Did you core sample the stringer behind the mount to see if the rot got there? I know my stringer rotted thru to the mount but only part way into the mount itself.... My fix was this...


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alamantia

Petty Officer 2nd Class
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Dec 16, 2011
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Epoxy or resin?

Epoxy or resin?

Newbie question here but I have a 1987 wellcraft Elite with a 360/5.7 mercruiser I/O the engine seems to have 4 mounts in total. Two in the back going to the coupler houseing / gimbal bearing area and on each side of the engine there are engine mount brackets lag bolted to blocks of wood. These blocks of wood are about 36" long and bonded to the hull seperate from the stringers that run the length of the boat. These blocks of wood are incased in fiberglass. The other day when I was changing spark plugs I noticed that the port side engine mount was pushing the fiberglass on top of the block down. I hoisted the motor up and removed two lag bolts to find that the block has rotted out. I removed the bracket and cut the fiberglass around the top of the block and peeled it off. I would say more than 50% of that block is rotted out. I started scooping the wood out and it got dark so I came in for a shower and a beer. Tomorrow after work I am going to remove the rest of the wood and clean the hull real well with acetone. I will have to buy a new block of wood. I am thinking a pressure treated 6x6 and cut it to length and plane it to match the angle of the hull (I think about 15deg?) But before I lay it in there I want to apply some sort of bonding material so that block of wood afixes itself to the hull and let it cure before I glass over the top of it and rest the engine on it. I was going to buy a gallon of polyester resen and some fiber cloth glass in the top of the block before I drop the engin on it. I just dont know what to use to bond the block to the hull. Will polyester resin work on the bottom of the block to bond it to the hull? Or do I also have to buy epoxy for that job?
 

Tthomp3

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Re: Epoxy or resin?

Re: Epoxy or resin?

i would bed it in PB which is a thickened resin with milled fibers. Use poly resin if thats what your going to use, mix in your milled fibers (1/4 inch chopped strand), mix in your hardener, and add cabosil to thicken it up to a peanut butter consistency, You could use PL adhesive if you don't want to go the PB route but it has to be bonded to the hull before you can glass.
 

PaJon

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Sep 30, 2011
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Re: Epoxy or resin?

Re: Epoxy or resin?

If the motor mount block is rotted, you prob have other problems too. Drill test holes in the transom and stringers. If you find wet or rotted shavings from those holes, post pictures and get ready for some demolition.
 

rickryder

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Re: Epoxy or resin?

Re: Epoxy or resin?

You should keep your posts in the same place when talking about the same subject.... It will get confusing hopping around ;)

I do not recomend pressure treated lumber.....reason... it's wet with chemicals and you will have a hard time getting it to bond well. You will also need ACQ compliant fasteners so they don't rot... Just use 2x material... if you need 3" thick use 2 2x4's and so on... coat with resin,let it tack up,then put a layer of csm between them wet up with resin,clamp or screw together and let cure. If you want a solid block you can get untreated 6x6 at a lumber yard like Kuiken Brothers in Fairlawn,Elmwood Pk etc.

You can use epoxy or poly resin..... remember that if going with epoxy it cost more than poly and you will not be able to put poly over epoxy in the future....epoxy sticks to poly but not the other way around ;)
 

tpenfield

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Re: Epoxy or resin?

Re: Epoxy or resin?

You should keep your posts in the same place when talking about the same subject.... It will get confusing hopping around ;)


Yes, I thought you (alamantia) already have a thread going on this topic . . . anyway.

PT wood is going to be 'wet' and need to dry out (i.e. age) before anything will adhere to it. Also, were you able to reach 'fresh' wood in the engine mount 'block'? that area will also need to dry out. This is still a temporary fix, right?

If you could post a few pictures of where you are at so far, that would also be a great help.
 

Bondo

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Re: My idea for temporary stringer repair

You should keep your posts in the same place when talking about the same subject.... It will get confusing hopping around

Ayuh,.... All fixed...
 

alamantia

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Re: Epoxy or resin?

Re: Epoxy or resin?

If the motor mount block is rotted, you prob have other problems too. Drill test holes in the transom and stringers. If you find wet or rotted shavings from those holes, post pictures and get ready for some demolition.

No demolition. Just the motor mount block. The block comes close to the stringers and transom but doesnt touch either as they were glassed over before the block was glued into place. Good call by wellcraft I guess. Only the block is bad. I suspect that the manifold hose was leaking at one time and water found it's way down the lag bolt holes. I will replace it this weekend. Not the end of the world, I am still putting the boat in the water in a few weeks.


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alamantia

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Re: Epoxy or resin?

Re: Epoxy or resin?

Yes, I thought you (alamantia) already have a thread going on this topic . . . anyway.

PT wood is going to be 'wet' and need to dry out (i.e. age) before anything will adhere to it. Also, were you able to reach 'fresh' wood in the engine mount 'block'? that area will also need to dry out. This is still a temporary fix, right?

If you could post a few pictures of where you are at so far, that would also be a great help.

My bad, I searched for this post to add to it sunday night but didnt see it, seeing as how I guess the restoration forum moves fast.

I will do as rickryder says and look into regular wood opposed to PT, I figured PT would be less suceptable to rot if water ever gets in there again, but if resin wont stick to it, I guess I will have to find some maple or something.

Now that it is all riped out and I have identified that the stringer and transom look good. I am going to measure up the block I need and drop it in there. I have to cut it the same angle as the hull (looks like about 15deg, but I dont know for sure) and slather some resin on the block and drop it in place and glass over it. Then drop the engine down and lag bolt it in. This should result in a perminate fix as this will make the boat 100% rot free (from what I can tell anyway)

Thanks for all your help.
 

tpenfield

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Re: Epoxy or resin?

Re: Epoxy or resin?

Based on what we see in the picture, you might find that you will be removing most, if not all of the wood in the engine mount 'block'. If that is the only place that is showing rot, then your repair will probably more 'permanent' than 'temporary'..

As a suggestion . . . you could use wood that is more rot resistant, like red cedar or redwood, to rebuild the block. You could also go the sythetic fill route with Seacast or similar material.
 

alamantia

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Re: Epoxy or resin?

Re: Epoxy or resin?

Based on what we see in the picture, you might find that you will be removing most, if not all of the wood in the engine mount 'block'. If that is the only place that is showing rot, then your repair will probably more 'permanent' than 'temporary'..

As a suggestion . . . you could use wood that is more rot resistant, like red cedar or redwood, to rebuild the block. You could also go the sythetic fill route with Seacast or similar material.

Yeah man, I scooped all of the block out. All I can see now is the hull and the stringer, fully incased in glass, no black. Its like a big retanglular void. I have to scuff the current glass with a scotch brite and wipe it all down with acitone and mix some up some thick glass or epoxy and lay it in there and drop the block in. Should be pretty straight forward. I will take your suggestion of redwood or ceader into consideration when I hit up the lumberyard saturday. Thanks again.
 

Woodonglass

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Re: Epoxy or resin?

Re: Epoxy or resin?

I'd recommend fabricating it out of 3/4" ext. grade plywood laminations coated in epoxy. Predrill your bolt holes and coat everything with 3M4200 and it will last for decades.
 

Yacht Dr.

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Re: Epoxy or resin?

Re: Epoxy or resin?

Can you fit a 4x4 in there ?

YD.
 

Woodonglass

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Re: Epoxy or resin?

Re: Epoxy or resin?

Just about perfect for 5 plys of 3/4" plywood with just enough space for the PB to glue it all in place.;)
 

rickryder

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Re: Epoxy or resin?

Re: Epoxy or resin?

Pretty much it's a chunk of 6x6.... Layers of ply works or 3 pieces of 2x6 and 2 3/8" ply....PB or csm between all of it and clamped..

Other option is pour Nida Bond like I did.... It's a few bucks but it would be quick and never rot again....
 

alamantia

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Re: Epoxy or resin?

Re: Epoxy or resin?

Pretty much it's a chunk of 6x6.... Layers of ply works or 3 pieces of 2x6 and 2 3/8" ply....PB or csm between all of it and clamped..

Other option is pour Nida Bond like I did.... It's a few bucks but it would be quick and never rot again....

Cool, thanks. Got it all cleaned out last night, just have to cut up the wood and glass it in now. I think i will paint over it once it is complete. The rest of the bilige is white as I have seen in most boats. Can I just use white oil based paint or must i buy something specific for this area, bilige paint?

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Woodonglass

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Re: Epoxy or resin?

Re: Epoxy or resin?

I'd go ahead and buy Bilge Paint, or roll on some Gelcoat
 

Yacht Dr.

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Re: Epoxy or resin?

Re: Epoxy or resin?

Cool, thanks. Got it all cleaned out last night, just have to cut up the wood and glass it in now. I think i will paint over it once it is complete. The rest of the bilige is white as I have seen in most boats. Can I just use white oil based paint or must i buy something specific for this area, bilige paint?

I wouldnt be too fast on painting anything until you run the boat for a bit.

Raw glass will give you an idea if its delaminating..test it out for a bit first :) ..

How do you plan on glassin over the stringer once you install the log of wood ( 6x6 or plystack ) ?

I hope you plan to wrap it over the sides .. in which case your going to need to grind off all that gelcoat.

just wondering..

YD.
 
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