Cracked Johnson Cowling

Shootit

Cadet
Joined
Aug 17, 2010
Messages
19
Have just purchased a really tidy 15hp motor but there is a crack along the length of the engine cover on the top edge of 1 side.

Its currently got a strip of gaffer tape over it from the previous owner but id like to bring it back to as close to original as possible.

Can anyone here guide me on the best way to fibreglass this if thats the best way.

Should i use matting on the inside etc.
Any help much appreciated.

Adrian
 

jonesg

Admiral
Joined
Feb 22, 2008
Messages
7,198
Re: Cracked Johnson Cowling

LEave the tape on the outside if its aligned good and seals the joint,
wash the inside with warm soapy water, then wipe it down with acetone til its squeaky clean. It might make the plastic material slightly sticky but thats ok, at least it means the oil is gone. Sand it very lightly if its very smooth to give some bite.

Get some slow epoxy and glass cloth, I like 4 inch wide glass tape for these jobs. Brush the epoxy on, lay the tape down and fill the weave with just enough epoxy, don't add more than that, if you have mixed resin left over throw it away rather than slopping extra on.
Too much resin will float the glass off the surface and weaken the repair.
A 1 inch throw away brush is fine for this.

Avoid quick set epoxy, the better quality stuff is 4hr set plus 24 more hrs to fully cure. You won't need more than a pint.
 

Woodonglass

Supreme Mariner
Joined
Dec 29, 2009
Messages
25,929
Re: Cracked Johnson Cowling

If you want to fix the crack on the outside after you do jones'ies fix on the inside, take a nail or a scratch awl and "V" out the crack, wash it out with acetone and then use some bondo 3M Premium filler to fill it in and sand it smooth. You can get Johnson paint online and no one will ever know it was ever cracked, cept you of course.


I'm just sayin...:D
 

Yacht Dr.

Vice Admiral
Joined
Feb 26, 2005
Messages
5,581
Re: Cracked Johnson Cowling

Hello Shootit and welcom to Iboats..

Is this cowel fiberglass or plastic ?

YD.
 

Shootit

Cadet
Joined
Aug 17, 2010
Messages
19
Re: Cracked Johnson Cowling

Ummm good question:redface:

Its currently having a service so cant check i assumed Glass but could be wrong.

If its plastic i guess i have to use a different approach?

Anyone know what they used on a 88 Johnson 15HP?

Thanks very much to jonesg and Woodonglass for your help.

Adrian
 

Yacht Dr.

Vice Admiral
Joined
Feb 26, 2005
Messages
5,581
Re: Cracked Johnson Cowling

Hello Shoot..

Aye..if the cowel is Plastic then a different approach is needed..

Plasic welding or something equivalant would be used ( fiberglass does not like PVC that well ).

YD.
 
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