Engine mount repair

[tjizzle]

Hello everyone and thanks in advance for any help. I own a 1989 23ft WA cuddy cabin Magna made by Galaxy boats. After last trip out I noticed the glass on the one motor mount was cracking and mount was starting to sink in. Yesterday I got around to pulling engine and was able to do some looking around in bilge area. Did some drilling into stringers and transom and wood was dry for the most part. The bulkhead that separates gas tank from bilge area (where motor mounts are glassed to) was glassed before mounts were put in and the wood in there was dry. When mounts were glassed in they did not glass the end towards the transom to good and I believe this is where water got in them. So now that I have motor out my plan is to cut old mounts out down to hull,gring glass down till I got something good to attach new to. I plan to layer pieces of ext. plywood glued together with pl adhesive,glued to hull with same,tab them in and glass over it. I have watched others videos on here and think I am ready to try the fibergassing. I was hoping I could get some advice on what to use for this job and get an idea of how much materials I will need to order. I was hoping to use poly resin for this.The mounts that I will be covering are 25" long 4" wide and 10" in hieght. Sorry pics are not the greatest but its all I have for now. Thank you
TJ

 

[tjizzle]

Re: Engine mount repair

Any suggestions?

 

[81 Checkmate]

Re: Engine mount repair

No expert here.......Just a novice and learned everything from iboats. Here is some pics of my motor mount rebuilds. Used Accruo plywood as this is the best quality plywood.
I used Poly resin and their recomended fiberglass from Home Depot for my whole project........ Also used Bono fiberglass with short strand filler instead of making my own P.B.........US.Composits is another source for resin and glass.

Be sure to remove and feather back any cracked or broken old glass before aplying new glass........ I used Matt in strips to tab in...then matt over that....then cloth over the matt.

I am sure the experts will chime in!

Good luck!

 

[73Chrysler105]

Re: Engine mount repair

That wood may be dry but it's definitely rotted. It definitely needs to be replaced. I think you are going about it right. Good luck and keep us posted on the progress. Clean up everything down to the hull new wood and fiberglass and it will be solid.

 

[tjizzle]

Re: Engine mount repair

Thanks for the response checkmate. When u say matt Im guessing thats csm,any specific weight on that and how many layers, and with the cloth im guessing this is 1708 also how many layers of this? Sorry for all the questions I have never done fiberglass before and just want to make sure I am using the right materials for the job. Thanks again for your help.
TJ

 

[jigngrub]

Re: Engine mount repair

What color were the drill shavings in the stringers?... and what does "dry for the most part" mean"?

9 times out of 10 when you have rot like this it isn't confined to such a small area. Did you drill your transom to check for rot?

Your plan of action for the motor mount stringers sounds good.

 

[tjizzle]

Re: Engine mount repair

Thanks for replys, the drill shavings were light colored and dry,yes I did drill transom and findings were same. The dry for the most part was becuase there were some 2x4's above gas tank that were not glassed and are wet. I will be fixing these also.

 

[81 Checkmate]

Re: Engine mount repair

To answer your question on the fiberglass....i used the fiberglass (3M) that is with the resin (3M) .... Not sure what the weight is...... Yes Matt = CSM

I tabed all the intersecting edges with a strip of matt (Aprox 3" to 4" wide)....... Tabed it in...then Immediately used a whole peice of matt to overlap the strip and remaining wood......let cure overnight...then sanded with 80 grit...wiped down with Acetone........then layed cloth over all the intersections and wood that was coverd in matt..... Let cure.. Then sanded 80 grit on edges and used another layer matt on all open edges.

I coulda done it all at the same time (Layer the glass)...but you need to work very, very, fast before it sets... as i wanted to see how good it bonded before i went any further.

P.S. As Jig has said check all exsisting wood before doing this repair.....Now is the time to do it right!

 

[tjizzle]

Re: Engine mount repair

Thanks for info checkmate I appreciate your time. I did check stringers and transom and they were good. I think I got lucky because everything was glassed in before mounts went in,problem was they left back end of mounts pretty much open and over time I guess the water was getting into them. Thanks again for youre help
TJ

 

[81 Checkmate]

Re: Engine mount repair

TJ - Glad to help......Keep us posted on your progress.......And take alot of pics!

Good Luck with your project!

 

[tjizzle]

Re: Engine mount repair

Will do, just waiting for it to warm up a bit to get started. Thanks again
TJ

 

[tjizzle]

Re: Engine mount repair

Had a little time today to remove old motor mounts. Also did a little grinding but dont have proper grinding disc,have to get over to harbor freight.

 

[73Chrysler105]

Re: Engine mount repair

Am I seeing right that those stringers look hollow as well which means there is a lack of wood in there too.

 

[tjizzle]

Re: Engine mount repair

I think youre talking about bottom of picture that is where mounts attach to bulkhead,I have to cut and grind that still.

 

[mxcobra]

Re: Engine mount repair

I used microlam out of the trash at a contruction site
glued and presed it all in and together with pl. premiam then glassed it all in seemed to work good....
should be pics in my thread

 

[tjizzle]

Re: Engine mount repair

Thanks for the info cobra. When I glass this in I plan on tabbing with 1708 then 2 layers of 1.5 csm and then a final layer of 1708. Can anyone tell me if this sound good and will this be strong enough? Thank you
tj

 

[jigngrub]

Re: Engine mount repair

The above detail is the one used most by iboats members for tabbing in regular stringers, it's a minimum and you can use more plies if you want. You'll probably want to go heavier on the capping.

 

[tjizzle]

Re: Engine mount repair

Thanks for the reply jig. Even know these are the motor mounts am I still supposed to hold them up off the hull with dowes? Just was wondering because the wait of the motor being on them. Thank you for youre help I really appreciate it.
TJ

 

[jbcurt00]

Re: Engine mount repair

You only support the stringers off the hull until you can fill the void w/ PB or PL. PL will require 72hrs +/- to finish off gassing. Longer in cool temps...

 

[tjizzle]

Re: Engine mount repair

Okay thanks jb just wanted to make sure it was same for motor mounts.
TJ