1981 Bluefin Sportsman rebuild

Crawfish Dundee

Petty Officer 2nd Class
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Mar 16, 2017
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118
Are those 2 holes drilled through the bottom of the boat between the ribs?
No, I think that's debris / dirt. Thank you for the rivet info, I'll check it out.
I found 3" x 3" x 1/8" AL squares on fee bay, pre cut, I may purchasethem.
 
Joined
Mar 26, 2017
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Just posting on here to tag along. I recently obtained a 86 Bluefin Sportsman 1900 with the 2.3 i/o. Replacing a head gasket on it and gutting the interior as well.
 

redlinj

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Oct 4, 2007
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So have you figured out how you are going to flip the boat over? Two tractors with two loaders. Couldn't be easier and no visit to the chiropractor!
 

Crawfish Dundee

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So have you figured out how you are going to flip the boat over? Two tractors with two loaders. Couldn't be easier and no visit to the chiropractor!



I doubt i'd get both owners of both tractors together on the same day, I will have to choose one. But I plan to rope the front anchor hook to the tractor bucket with about a 4 or 5 foot lead and raise it a bit, and man handle the stern flip. Then build a dolly of some sort, maybe a box type cradle that sets on the boat trailer and tractor it on then push it into the garage. That's the plan, after the transom repair. It's not going to happen for a while, the weather here isn't ready, had snow today, really tired of that stuff.
 

Crawfish Dundee

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Mar 16, 2017
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Today I started the rebuild, moved the boat into an empty old garage on the farm and tore out the rotted transom. Tomorrows plan is to clean the aft end and get some fresh marine grade plywood cut and epoxied up to install possibly Monday after the morning's respects paid.
 

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Watermann

Starmada Splash of the Year 2014
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That transom was a rotten mess!

fetch


Don't skip the important step of leak testing and repairing any damaged rivets and leaks, especially in the keel area.
 

Crawfish Dundee

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Mar 16, 2017
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Yes it was. The previous owner just kept tightening the motor mount bolts and compressed the aluminum mounting plate because of the wood going soft. I will have to do some hammering to get it back into shape.
 

Crawfish Dundee

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Mar 16, 2017
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New transom wood epoxied together, two sheets of marine grade 3/4".
 

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Crawfish Dundee

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Plywood flooring thickness decisions.

16 ft aluminum, I'm trying to decide to go with 3/4 plywood, 5/8's or half inch.
Will resin added to both sides of 1/2 inch be stiff enough?
I will resin coat what ever size I decide to use, 3/4 just seems like overkill and just will add weight to the boat.
I plan to add a second sub square of ply under where pedastal seats will go.
Our local lumber yard only carries 3/4 and 1/2. 5/8" is special order, but available.
Will 1/2" be thick enough not to flex?
 

Bondo

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Will 1/2" be thick enough not to flex?

Ayuh,.... How long is the plywood span from bulkhead to bulkhead, stringer to stringer,....

If ya resin, 'n glass the 1/2", it oughta be just fine,....
Just resin is useless,....
 

ondarvr

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Apr 6, 2005
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Resin alone will not increase the stiffness, and what resin do you plan to use/

​I'm not sure why people think they need to increase the plywood thickness up to 3/4" on small aluminum boats, most of the time 1/2" is fine, but it depends on the support structure under it. I'm not pointing at you on this, it seems to be a general theme, if 1/2" works, 5/8" must be better, so 3/4" should be great. Having a small amount of flex is a non issue, and 90% of the time you will never notice it.

​The increased weight on a small boat is far more of an issue than a slight amount of flex. There are situations where 3/4" may be needed, but not often.

Use whatever thickness ply was there to start with.
 

gm280

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Jun 26, 2011
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You didn't provide any substructure info. If your are trying to span side to side and front to back without anything underneath. NO 1/2" will not work! It will be springy forever. On the other hand, if you have stringers and bulkheads spaced properly underneath, the yes 1/2" coated on ALL sides with fiberglass materials and resin will work perfectly. JMHO
 

Crawfish Dundee

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72 inch beam, 64 inch wide floor, with two aluminum stringers in the center about 16" apart.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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I would use 1/2" with a layer of CSM, a layer of 1708 and a top layer of CSM on both sides, and foam under it myself
 

jbcurt00

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Crawfish, you could ask this in your Bluefin topic, then all the how wide and support questions wouldnt have been as necessary.

What are you planning on covering the deck w? Vinyl? Paint?

These ^^^ questions, might not have been necessary if this was part in your rebuild topic
http://forums.iboats.com/forum/boat...epair/10357249-1981-bluefin-sportsman-rebuild

Asking about plywood w out details about what boat slows the helpfulness of replies too.....
 

Crawfish Dundee

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Mar 16, 2017
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Crawfish, you could ask this in your Bluefin topic, then all the how wide and support questions wouldnt have been as necessary.

What are you planning on covering the deck w? Vinyl? Paint?

These ^^^ questions, might not have been necessary if this was part in your rebuild topic
http://forums.iboats.com/forum/boat...epair/10357249-1981-bluefin-sportsman-rebuild

Asking about plywood w out details about what boat slows the helpfulness of replies too.....

Going with vinyl. Can a mod transfer this post over to my build thread then?
 

Watermann

Starmada Splash of the Year 2014
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For the base level decking 1/2" ply is all I've used. Remember it's supported with the rigid foam board too if you lay it in correctly that is. Small AL boats do not need to be made to have dance floors or be aircraft carriers. Just make sure the ply is good 5 layer 1/2" fir marine or exterior grade that doesn't have all the defects like voids and knots all over.

The ply seams will need more support than factory, just having a simple joining strip of AL should be replaced with some angle AL that spans the deck supports.

Now if you have any elevated decking with hatch cutouts and pedestal seating then you would need 5/8" or maybe even 3/4" along with good support structure. I've used both and prefer to work with 5/8" for this. My fishing buddies like to eat so I've had to build for that too :lol:
 

dusted_ya

Seaman Apprentice
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Mar 22, 2008
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I added extra gussets between the stringers top and bottom with larger rivets then used pour in structural foam (huge PITA) to make the hull extremely rigid. (rides like a fiberglass boat without the weight) If you don't modify it from stock then 3/4" ply will increase rigidity.
Don't worry about adding weight.as it's below water line so that in itself will increase stability.
 

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ezmobee

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Mar 26, 2007
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I put 3/4" in both my restores. I really like how rock solid it is. 5/8" might be nearly as good but wasn't as readily available. I find 1/2" to be too springy.
 

Crawfish Dundee

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then used pour in structural foam (huge PITA) to make the hull extremely rigid.

What pound foam did you use? I use 5 lb. at work, kinda pricy at $425 for a 5 gallon kit. I may use foam board and spot pour the two part foam in key places.

Thank you to all who have replied with suggestions and tips.
 
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