1972 19' 1" Gull Aquasport rebuild- finally back at it

[Tim/GA]

Warthog, stringers are layed on 1/4 plywood form.  1 layer of 9 oz inside and one layer of 1708 outside, then tabbed in with 6oz tape, then 1708 biaxial "tape".  Last I layed a final layer of 1708 that stretches from about 2" beyond the tape across the stringer and over the keel.  Other side same thing and the last layer also overlaps over the keel.  All told, one layer of 9 oz, 1/4 luan, and two layers of 1708.  In some of the pics you only see the one layer as they stringers are not installed yet.  And in the last pics the ends of the stringers do only have one layer since I will need to overlap the new glass to tie in the stringers to the stern.  Hopefully enough as I am beyond the point of no return!  Thoughts?

I thought about larger or more tubes but in a boat this size I am a bit limited.  This will give me a smaller wiring tube lone each side of the boat and a large one for the hydraulic steering lines along the other.  The fuel line is in a different tube.

[Tim/GA]

Anyone else ever wish they could be in a dark alley when you ran across the idiot who did some "modifications" to a boat you are working on?  I am a relatively peaceful person but after the past few days I would gladly run into them right now!

Ok, the run down so far.  Someone decided to put a under deck fuel tank into the boat.  They apprently had an aluminum tank laying around that would not fit in the space between the stringers.  So what to do- well lets just cut out half of each of the main center stringers, they really are not that important- right?  And then they did not even bother to glass over the cut areas, just left the foam exposed.  Top it off by foaming in the tank right to the hull of the boat so that it can corrode and leak.  The guy I bought the boat from (for $400- including a marginal trailer, new leaning post and hydraulic steering) is lucky he did not blow up with his family.  Oh, and then water started leaking at the chines.

Now I find that someone, probably the same person, decided to raise the transom height to 25", not a bad idea but crappy execution.  They added a section to raise the height and then scabbed on an extra 3/4 of an inch of plywood to the inside of the transom.  Just getting this added stuff off has been a trip, now I still have to get the 34 year old wood out from the original transom.  Oh well, it will sure be nice when done- in 2010!
Ok, done ranting. I feel better!

[Tim/GA]

The transom is out!  That was NOT fun, just getting the extra inch+ that someone added to the inside was bad enough.  And the extension they added to raise the transom to 25", while not how I would do it, was on there pretty good.  The old wood from the original part of the transom was not in horrible shape considering the age, that just made it all the worse to get out though.

Here you can see the inner part that was scabbed onto the transom and the extension added to the top of the transom.  Used a circular saw to score just through the add on and a couple of pry bars to take it off.


This side was particularly subborn!


I did manage to get half of the thickness of the original transom out in mostly one piece.  It will make cutting the new pieces much easier.  Only lost the one side at the top and can transfer from the other.  Lots of work with a chisel to start the separation and then multiple pry bars and wedges to pound down into the crack did the trick.


And it is finally done, sanded and ground and pretty much ready for the new core!  If you look on the left side of the pic you can see a large patch of the transom skin that is a different color.  One of the main reasons I ripped out the transom was that it sounded like the skin had delaminated from the wood or the wood was rotten in that area.  Turns out the delamination was between 2 of the layers of the outer skin but the wood was sound and attached to the inner skin.  As near as I can tell that might have been that way since the factory!  Oh yeah, evicted a colony of the smallest ants in that area.  You should have seen them all running out a screw hole at the bottom of the skin.


And now, to put it back in.  Plan is to use a layer of 1708 on the inside of the outer skin (extra build up for the part that was delaminated) and then 3 layers of 1/2 plywood with 1708 in between each (or would 2 layers of 3/4 inch be better if I can get it?  Fillets and biaxial tabbing around the edges and 2 layers of 1708 on the inside.  These will wrap up and over the top of the transom and down to the old skin that will be ground back (the top 5 inches of the transom will not have any old skin since that was 20" to start).  I will use 6 ounce on the part of the transom that is visible once the floor is in to help with fairing.  Any thoughts or problems with this that you all see?  Would it be better to assemble the core outside of the boat and let it set so it can be put in all at once?  This might be possible but might not due to sapce.  Should I lay more glass on the inner and outer skin that I planned above?  When I am glueing, depending on the part, I sometimes add 1/4" chopped glass strands to the cabosil putty for extra strength- what is best to use on the transom and around the edges?  Thanks for the ideas and help.

[warthog5]

3 layers of 1/2 plywood with 1708 in between each (or would 2 layers of 3/4 inch be better if I can get it? Fillets and biaxial tabbing around the edges and 2 layers of 1708 on the inside.

You will use less material's if you use 2 layer's of 3/4in.

Some folk's like a layer of 1 1/2oz matt between the plywood layer's. I just use stright epoxy to wet the wood out well, let it sit for 20min's and wet it again. Then trowel on epoxy/cabisol and stick them together. I predrill hole's to use temp. drywall screw's as clamp's. I remove them after 4 to 5hrs depending on temp's.

Use at least 3 layer's of the 1708 or 1808 on the inside skin. #1 45/45, #2  0/09, #3  45/45

[Tim/GA]

Thanks I am going to find the 3/4" then and not put the glass between them.  I do think I will add the 1/4" chopped glass to the resin and cabosil though, that is some of the strongest "glue" I have used.  I only have 45 degree 1708 on hand but will cut and run the middle layer to be 90 degrees, had not thought about that.

I had planned to use screws to clamp the core together and also to clamp the core to the outer skin/glass.  I have noticed many of the pics of transom work (including yours I think) showed others using bolts and wood to clamp.  Is this necessary?  I was even thinking about using waxed shower board (the thin, slick board I used for dry erase boards) on the outside of the transom.  This would let me fill the many holes in the old glass prior to laying on the next layer of glass.  I had planned on screwing through this and the outer skin into the core.
Thanks again.

[warthog5]

You want good even presure when clamping.

The setup I used will give you that and pull the transom skin stright and even preasure.

Sometime's they will have a bow in them after the coring is all gone.

I used long 1/4in bolt's and fender washer's thrubolted thru 2 X 4's that were wraped with visqueen and stapled to the wood. This will keep from gluing the wood to the boat when you have squeeze out.

[Tim/GA]

Warthog, hope you don't mind a few more quesitons!

I am checking out your rebuild and looking at how you did the transom right now.  I can see how you used the Visqueen wrapped braces inside and out and the bolts.  I am planning to go that route as well, but I also see above where you mention using the drywall screws.  Did you use those as well as the bolts/braces I can see or were you talking about using them to help pull the 2 layers of my core together from the inside and NOT through the outer skin?  
I also had planned on using fillets and glass along the transition from hull side and bottom to the transom skin.  Then a layer of 1708 on skin and the core.  Last question for tonight!  Should I fillet and tape the inside of the transom core before the 3 layers of 1708 or cut the 1708 to stagger and overlap the hull sides and bottom?
Thanks again.  Any tips from anyone else?

[warthog5]

Let's see if I can remember everything?

The drywall screw's are just temp. to glue the 2 pieces of 3/4in plywood together on the bench. They are removed before the resign has had time to do a full cure. aprox 4hrs latter.

When the core goes in the boat no drywall screws are used. Thrubolted w/ the wraped block's.

Yes a fillet is run around the core edge after the core is installed and the block's removed.
Then each piece of glass laminate overlap's the side's & bottom getting bigger overlap's for each layer is laid.

[Tim/GA]

Thanks, hope to get at putting the transom back in this weekend.

[warthog5]

Before you start your glue up with the 2 piece's of plywood. Predrill hole's for the drywall screw's and be sure to remove the burr on the backside so the panel's lay perfectly flat.

I also use plastic milk jug cap's as washer's.
This keep's the oozz out from sticking to the screw head's.

[Tim/GA]

Are 2 layers of 3/4" going to be strong enough with the outer and inner fiberglass?  The original transom appeared to be 1 1/2 thick but with the add ons that someone did it was more like 2 3/4 when I took it out.  I am planning on either a 150 or going lighter with a V-4, not sure what the engine will be right now though.

[Tim/GA]

Between teaching, getting ready to move, making beach/shrimp seines (season is on down here) and being sick- not as much progress to report as I would like!  

Last weekend I did get the transom core cut and glassed together.  I used 2 layers of 3/4" plywood with a layer of 1708 in between.  Heavily wetted out the wood 2 times and then layed in the glass between them and screwed the pieces together.  Took warthogs advice and predrilled the top layer for the screws.  Unfortunately that was as far as I got last weekend.

Ended up spending Sat. this weekend getting a rush ordered net done- also still trying to get over this cold/sinus whatever it is.  Sunday I did a bit more grinding on the transom skin and completely mocked up the transom core with the thru bolts and blocks.  Took some time but well worth it.


Ended the day by laying a layer of 1708 on the inside of the existing transom skin and around the edge of the sides.  Wanted a bit more thickness but wanted it to set up some before installing the core.  Also filled the screw holes left from the layup of the core.
First thing this morning I wrapped the blocks in plastic (hopefully will be enough since I don't have Visqueen) and waxed the bolts.  Wetted out the core 2 times and the transom skin once.  Troweled on epoxy thickened with cabosil- layed it on the core- and layed the core in place using the bolts and blocks to get a good tight fit between the core and the transom skin.



Cleaned up the ooze in a few places and decided to get out of the heat.  Hear thunder out there now anyway.

How long should I leave the bolts and blocks in place?  Actually, this may be academic in that I don't want to pull them today since I finished about 12:30 and am using slow hardener.  Most likely will not be able to pull them until Wed., maybe even Thursday.

Next up, lay 3 layers of 1708 over the inner transom and build the last 5 ft of the stringers.

[JimCt]

Hope the rain doesn't screw up the slow cure epoxy...

[Tim/GA]

Should not be a problem.  The rain storm only lasted about 20 minutes, pretty typical for GA summers.  The boat is under a cover and the temp is back up to 85 already.  The slow hardner I am using is pretty much made for high heat and humidity, will have to get some other hardner for winter use though.  Might be a bit longer cure time but I will be leaving the bolts in for a few days anyway.

Does rain (not right on the piece of course) affect polyester resin worse than epoxy?

[JimCt]

Not sure if high humidity affects polyester resin cure but with the all the work & cost of materials I like to keep things as dry as possible.

Project looks good!