Making an Engine Bracket
 

Go easy on me boys as this is my first time. I decided to give a try at building a engine bracket for my 23CC. I have a yamaha 250 that is supposed to hang off the back of this thing. I may or may not put a kicker on it as well. The bracket has a 48 inch wide flotation chamber and a 30 inch set back. The swim platform will be 84 inches long by 27 inches wide.

I started by making a 1 off mold out of 1/2 inch MDF for the flotation chamber. After cutting the mold pieces I tacked them together with finish nails and put some fiberglass tape around the edges to hold the mold together. I used bondo to make the rounded courners on the inside of the mold. Bondo hardens fast so you dont have to wait a long time for it to dry because there is a lot of sanding needed to make the corners smooth. Two coats of epoxy on the inside of the mold and sanding with fine grit over each coat helped to make it smooth. I put 4-5 coats of wax over the entire mold buffing out each coat.

For the lay up I used System 3's 2/1 epoxy. They have different hardeners that you can mix together to get the right working time for your lay up. I put three coats of Duratec sanding primer over the inside of the mold. I used 1808 biaxial cloth for the entire lay up. I overlapped all the corners and then reinforced the corners with 8 inch tape. The layup was hard for me because of the thickness of the bracket and I needed to pay attention to structural detail. The finished shell of the flotation chamber has a 1/2 inch thick lay up on the front, back, bottom and sides. The corners are 1 inch thick lay up.
I glassed a core transom into place with a 1/4 inch thick lay up on the inside of the bracket. Next I glassed in some stringers made out of 2 pieces of 5/8 inch corecell glued together.

I'm currently working on the mold for the swim platform and will start the lay up of that this week. The swim platform will be bonded to the flotation chamber with cabosil. I am glassing in a lip that goes around the inner edge of the flotation chamber for the swim platform to adhere to. I have two 8 inch armstrong round hatch plates for access to the inside of the bracket.

The bracket is still a long ways off from being finished. Like I said I still need to make the swim platform. Also there is some fairing and sanding that needs to happen due to some imperfections of the inside of the mold. It will have to be painted as well.

I wanted to thank some of the fellas on Classic SeaCraft who helped me by sending pictures of their brackets. I would not have had a clue as to were to start. Here are a few pics of the project and a link with a photo gallery of all of the pictures I have so far. I will post again when it is all finished.

http://www.casdvm.com/photos/DSCN3605.JPG
http://www.casdvm.com/photos/DSCN3612.JPG
http://www.casdvm.com/photos/DSCN3626.JPG
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http://www.casdvm.com/photos/DSCN3683.JPG
http://www.casdvm.com/photos/DSCN3700.JPG
http://www.casdvm.com/photos/DSCN3691.JPG
http://www.casdvm.com/photos/DSCN3713.JPG


http://www.casdvm.com/photos/Bracket/index.htm

Strick

Re: Making an Engine Bracket
 

As always... nice work.

Re: Making an Engine Bracket
 

Strick,
I should have known you would be the one to do this, the quality of your glass work is phenomenal. I can't wait to see the end result. I am going to try to do this on my MA, I can only hope it comes out half as nice. Keep the pic's coming.

Pat

Re: Making an Engine Bracket
 

Looks great!! What's the transom core material on either side of the marine ply?

Re: Making an Engine Bracket
 

Outstanding Strick [img]/images/graemlins/cool.gif[/img]

Maybe a built-in insulted 12 pack size box type cooler in each chamber before you seal the platform on would be a thought??? Access through the top port holes. Keep bait, beer or even small dry storage or whatever, drain them to the main chamber drain.... [img]/images/graemlins/grin.gif[/img]

Re: Making an Engine Bracket
 

Again looks great, I know AFTER I did my transom I started thinking “I wonder if one could build a intergraded bracket WHILE you are redoing your transom”??? Sooner or later some one probably on this board will try to do that but in the mean time your approach looks great.
FellowShip [img]/images/graemlins/grin.gif[/img]

Re: Making an Engine Bracket
 

Looks good-

Only issue I can see is water getting trapped in between the stringers?

Re: Making an Engine Bracket
 

Thanks fellas

I guess well see if it works when I that engine on the back of it [img]/images/graemlins/confused.gif[/img] The transom core is 3/4 inch plywood sandwiched between two layers of 5/8 corecell. After I did it it thought that I should have done it the other way around and sandwiched a piece of corecell between two pieces of plywood. I have a drain in the center stringer but Trayder is right and I need to add one on each of the outside stringers before I close it all up. Here are a couple more pics.

Strick

http://www.casdvm.com/photos/DSCN3666.JPG
http://www.casdvm.com/photos/DSCN3721.JPG
http://www.casdvm.com/photos/DSCN3722.JPG

Re: Making an Engine Bracket
 

Strick-

I leaned the hard way, I forgot to put drain holes in my outer stringers and let me tell you much of a pain it has been finding a fix after the deck was in...... I did fix the issue but trust me I will never forget again.

All the water that accumulated in my outer stringer area was Condensation but after a few months of vastly differing temps that condensation accumulates very rapidly.

One drain hole in the aft corner of each stringer is all you will need.

Your bracket looks great, and oddly familiar [img]/images/graemlins/wink.gif[/img]

Re: Making an Engine Bracket
 

I'll drill a couple one inch holes and seal with cabosil and that should do the trick.

Today one our fellow SeaCrafters Tim Barber aka Bigshrimpin paid me a visit. It was great to see Tim and talk with him about SeaCraft's and boats in general. Tim not only stopped by to shoot the $h#t but was kind enough to roll up his sleeves and dig right in. Here are a few pics of what we did today. We applied 3 coats of wax over the swim platform mold and applied two layers of 1808. We then cut some corecell to fit and glued it in place. Tomorrow I hope to finish the paltform pop it off the mold and see if it fits the bracket [img]/images/graemlins/confused.gif[/img]

Strick

http://www.casdvm.com/photos/DSCN3727.JPG
http://www.casdvm.com/photos/DSCN3733.JPG
http://www.casdvm.com/photos/DSCN3734.JPG

Re: Making an Engine Bracket
 

This next secuence of pic's shows the swim platform after the lay up is complete. The final tally was 2 layers of 1808 then the corecell then 2 more layers of 1808. Then one time around the edges and corners with 6 inch 1708 tape. It broke loose from the mold without any difficulty. It weighs I'm guessing about 20 pounds max. The textured surface was a little blotchy but I think I can still make it work for me. After freeing it from the mold I trimmed off the excess fiberglass and cut it to fit the flotation chamber. Lucky me it fit's perfect! I'm going to have a some fairing and sanding to do but it should look good when it's all finished. I'll post pic's when I get the whole thing complete. Here are a few pics along with a link with all the pics of the project. http://www.casdvm.com/photos/swimplatform2/

Strick

http://www.casdvm.com/photos/DSCN3746.JPG
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http://www.casdvm.com/photos/DSCN3778.JPG

Re: Making an Engine Bracket
 

Wow . . . That came out really nice. The platform fits on perfectly.

Re: Making an Engine Bracket
 

That looks great. What a professional job. You should pull a fiberglass mold on the finished unit.

Re: Making an Engine Bracket
 

Thanks Wild thang. Welcome to the board.

I've finished the bracket. It just needs to be mounted and painted. Things do not always go as planned like usual. My non skid surface from the FRP mold did not really come out that great so I decided to just fair over it all with epoxy/cabosil. If I were to use the stuff again I would put two heavy layers of epoxy over it before laying up the glass. There were several areas were the glass was not saturated anough and left it blotchy. Another big mistake was putting duratec as a first layer in the mold. It did not adhere that well to the glass and I had to grind it off and re-primer with the duratec after a bit of fairing and sanding. I talked with Ringleader about this and he thinks that if I had let the duratec dry and then sanded it then it may have adhered to the epoxy OK. I bonded the two parts together with cabosil/epoxy. I still dont kow how much it weighs but I can move it around easily by myself. I'll take it to a scale and weigh it later. I'm done making molds for accessories on this boat right now but in the future if I do any big mold projects I will try working with gel coat and vinylester resin. The following pictures are for your enjoyment.

http://www.casdvm.com/photos/DSCN3813.JPG
http://www.casdvm.com/photos/DSCN3818.JPG
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http://www.casdvm.com/photos/DSCN3826.JPG http://www.casdvm.com/photos/DSCN3836.JPG
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http://www.casdvm.com/photos/DSCN3858.JPG


Strick

Re: Making an Engine Bracket
 

Incredible work, Can't wait to see the finished boat.

Re: Making an Engine Bracket
 

Strick'
Nice work. I wish I had found this board sooner. I could have saved you a pile of time bye passing along some tricks about making MDF molds. I have made more than I can count using MDF and Duratech.
Bill

Re: Making an Engine Bracket
 

Dave- Thanks. It's gonna be a while before she is done. I need to start taking some time off work if I'm gonna get her done by fall.

Bill- Shoot me a e-mail as I'd love to get some pointers. As of yet all I've had a my own experience to go by so I would like to talk to someone who has been in the industry. casdvm@msn.com