mini jack plate

[justfishin2]

OK, I know that the "standard" measurement for a long shaft is 20" and that is usually measured from the bottom of the clamp bracket to the anti-cav. plate. I'm getting ready to install a mini jack plate on my transom which is for a short (15") shaft. Isn't the best way to do this to actually hang the long shaft motor first and measure how low it is in relation to the bottom of the keel then install the jacker to make up the difference? In other words, if I install the jacker based on the assumed difference (20 minus 15=5") it could well be off due to several variables. Am I correct in thinking this?

[Cray]

That's what I would do. If I'm not mistaken those have about a 4 in rise in them and maybe 4 offset. I would want the jacket to have good support on the transom at top bolts. Think I would put a backing plate on the inside. Nothing drastic but just a little added support. You could probably put it up there with some clamps and take measurements to get it where you want it.

[justfishin2]

Cray, I have two pieces of 3/8" thick aluminum strap (1 1/2 x 7) that I plan on using on the inside of the transom for additional support. I'm going to use 6- 3/8 x 3 stainless bolts with locknuts which will go through the jacker, transom and the straps. Hopefully that will be adequate. About the only other thing I'm not sure of is the plywood backer that came with the jacker. It does not appear to be treated with anything, and I'm thinking of just soaking it with spar varnish or urethane. Any thoughts on this?

[Cray]

I have always used spar varnish. First coat let sit for 3/4 days. Then another good coat. Has held up real well for me.

[skeetbum]

When I built boats for Correct Craft, any first coats were extra generous and thinned 50/50 to allow them to soak way back in before they harden. We used fiberglass resin but having done the same with GOOD polyurethane has worked very well for me. Crays dry time sounds good to me also.