Ms. MAK 20SF

[slowJEEP]

Any ideas what this tube is for?




Inner transom skin came out without too much fuss.




No real surprises here. All the wood is rotten. There was uncoated transom wood exposed inside of the stringers. There's water in the stringers but not soaked into the foam. Is it possible they used closed cell in '88?

[FAS]

I believe those small tubes were used to pull the hull from the molds, after the layup was done small cardboard tubes and two or so layers of heavy woven roving, put chains thru and pull it out...

[slowJEEP]

Sounds good to me FAS. That'd explain the one underneath the front deck.

Removed a little more glass today. Looks like the tabbing from one of the stringers to the hull has delaminated the full length. Gave me a good opportunity to check the condition of the foam in a different location. Seems to be pretty healthy for the most part.

Need to gather some equipment to prep the hull for repair. I've been looking at the Bosch ROS65VCL DA sander and Makita 9237CX2 7" polishing/grinder. Any thoughts on a 600-3000 rpm polisher w/ abrasive disk for grinding fiberglass vs a regular ol' dewalt 7" grinder?

Latest of the transom



Last of the wood

[wattaway2]

Try the 6" porta cable electric DA my buddy that worked for Lazzara has sworn by them for years but stay with there pads something about there weight and flex ability

[Normagain]

Originally Posted by slowJEEP

Any thoughts on a 600-3000 rpm polisher w/ abrasive disk for grinding fiberglass vs a regular ol' dewalt 7" grinder?

Haven't been able to beat a grinder with flapper discs, I think 36 grit. They last and work fast for rough work.

[FLexpat]

Originally Posted by Normagain

Haven't been able to beat a grinder with flapper discs, I think 36 grit. They last and work fast for rough work.

X2
I use a Porter Cable 6" DA with flappers for removing glass. Just got a 6" buffing disk for it to work the gelcoat.
I also use a 4" angle grinder; sometimes with grinding disks and sometimes with cut-off disks when I am making thin cuts. Use good gloves if you take the wheel guard off - it has saved my fingers a couple of times.
And I use one of the Rigid multi-tools to get where nothing else can.

[Blue_Heron]

Originally Posted by slowJEEP

...Any thoughts on a 600-3000 rpm polisher w/ abrasive disk for grinding fiberglass vs a regular ol' dewalt 7" grinder?

I have a couple of these:

http://www.homedepot.com/p/RIDGID-15...ct_description

Fiberglass is fatal to electric tools, eventually. I had a cheap sander polisher that died pretty quickly. The Rigid 7" grinder at 8000 rpm works circles around the sander polisher, especially if you use the flapper disks Normagain suggested. The quality of Rigid's power tools is on par with Porter Cable, Bosch, Makita, or DeWalt.

There are two things I like about the Rigid product over the competition. One, the trigger handle rotates 90° right or left. That makes it very comfortable to use if you are using a cutoff blade or grinding at odd angles.

The second thing is the lifetime guarantee. Technically, you have to register your purchase for the guarantee to take effect, but there may be a little wiggle room on that. Home depot replaced one that I hadn't registered. It was several years old, and I had misplaced my receipt. I'm sold on them.

Dave

[slowJEEP]

That Rigid Grinder is genius. Thanks all for the suggestions.

Onto another matter. It's time to order material and I'm wanting to go with Coosa BW26 for the transom with epoxy.

I'd say the stuff that came out of the transom was 1.5"s thick and it'd be safe to replace it with the same thickness. However, since I'm going to run a full width dive platform/engine bracket, I was thinking about going with 1" coosa. I'm fielding opinions so please comment.

I know the 1/12*b*h^3 means it will be roughly a 3.375x decrease in stiffness/strength from 1.5" to 1" but I expect the bracket will more than make up for it.

My desire to skimp on material is the proportional decrease in weight and $. I figured I was bias and could be set straight by the CSCers.

[FAS]

I would go by experience,not numbers,1" foam for a transom is not enough if want to feel confident that you did the right thing. I am sure it would work, but...

[FLexpat]

Not sure about the 20 but on my 23 it was 2 layers of 5/8" stapled together. Something to think about; You are adding a pretty good sized lever arm with that platform and you really don't want the transom flexing but you are right to be thinking about weight. The volume of the 1.5" transom in my 23 is 3 ft3; 78 lbs of Coosa 26 and 100-120 lbs if plywood. A 1" Coosa 26 core would weigh 50 lbs for a savings of 26 lbs. over the 1.5" coosa. Not a lot of weight savings, maybe a little in $.