How can i repair the cut out i did in the side of the stringer?

[exnavyman123]

Re: How can i repair the cut out i did in the side of the stringer?

The motor is a outboard, still on. I assume that area i cut out is part of the stringer system, not sure, there is a "rib" exactly like the one i cut out closer to the side of the boat on each side, which looking at the picture of the back of the boat you can see that "rib" area that goes a little lower than the bottom of the boat where the fish finder is screwed to, this is the only part of this connected "system" that extends all the way to the back of the boat, that may be the actual stringer support?

to screw back in that area i cut out, which is the same exact size as the hole so i assume i have to screw to that cut out piece something that extends larger that the hole to run the screws into the part that is still there , through the piece i'm putting back in correct?

 

[oops!]

Re: How can i repair the cut out i did in the side of the stringer?

yep.....just screw it so it stays there so you can glass over it..it will be easier than glassing a new part

 

[Yacht Dr.]

Re: How can i repair the cut out i did in the side of the stringer?

View attachment 112318

Attached is a pic of someone elses 1988 winner

The pics I think we are all waiting for is the overall pics of YOUR boat .. I see loads of close ups and semi close ups..but no Over all aspect view of the repair area. ( you confused oops already with the " have you removed the motor yet " ).

Im thinking of a different repair schedule then what has been given here because I have worked with single molded stringer systems..

I think your going to bevel your stringer "Part" ( not the cut out piece(s) ) .. then make a mold/backing from the inside of your stringer to apply a pileup of glass. ( I would not use the existing cutout piece(s) for your repair ). It looks like the cut out is in two pieces .. not just one solid cutout. Too much complication with this trying to puzzle piece them back together IMHO. Its just how your pics of the stringer cutout looks in two cuts ..

BTW .. Is this ONE repair or two ? .. Your pics kinda look like 2 separate cutouts.

Over all pics would still help greatly ..

YD.

 

[exnavyman123]

Re: How can i repair the cut out i did in the side of the stringer?

ok thanks oops, can i do the repair like this:

The top section of the fiberglass is cut all the way through however the foam is holding it hard, i can put it off if i pulled really really hard, so can i leave the top part there and use peanut butter to seal the cracks , then when it hardens, grind all the gel coat off the top area in a circle all aound the top part and dish it out and use csm layers small then bigger to glass over the top then when that hardens screw the cut out piece back into the inside of the cutout area and grind that area dishing it out and doing the same there?

 

[exnavyman123]

Re: How can i repair the cut out i did in the side of the stringer?

Hey Yacht, the area i cut, not the grinded area of the wood mounting block glassed in, i cut in a upside down L shape, the top of the stringer is still on there with the foam underneath holding it there hard, the rectangle shaped missing piece i took totally out, my above post # 24 is how i was thinking this needs to be done. ?

 

[exnavyman123]

Re: How can i repair the cut out i did in the side of the stringer?

I'm hoping this pic serves as a overall pic. The yellowish thing you see on the right is one of the 2 gas tanks 14 gal. The farthest back area (dirty looking area) is the transom area where the motor bolt heads are ( higher up to the left) the closest area in the pic is the bilge area where the bilge pump was mounted to the block of wood glassed over i grounded off the gelcoat and glass. The other side of the boat looks exactly the same, another gas tank, another raised rib stringer section there too, total of 4 ribs on the bottom ( 1 closest to the side of the boat then going inward the area i cut, bilge in middle and 2 more on the other side, 1 is under the gas tank to the right of the gas tank in the middle.

 

[Yacht Dr.]

Re: How can i repair the cut out i did in the side of the stringer?

Hey Yacht, the area i cut, not the grinded area of the wood mounting block glassed in, i cut in a upside down L shape, the top of the stringer is still on there with the foam underneath holding it there hard, the rectangle shaped missing piece i took totally out, my above post # 24 is how i was thinking this needs to be done. ?

I would not do it this way .. I didnt realize you already had a cut piece that was not removed and foamed backer ..

ok thanks oops, can i do the repair like this:

The top section of the fiberglass is cut all the way through however the foam is holding it hard, i can put it off if i pulled really really hard, so can i leave the top part there and use peanut butter to seal the cracks , then when it hardens, grind all the gel coat off the top area in a circle all aound the top part and dish it out and use csm layers small then bigger to glass over the top then when that hardens screw the cut out piece back into the inside of the cutout area and grind that area dishing it out and doing the same there?

If you can remove the L cutout I would. leaving just a larger "L" cut with some foam backing on the upper half that you can still work with for a template of the repair. The lower half without foam .. You can form it with a stir stick or two and some 5 min epoxy just to make a backing for your glass.

Basically your NOT going to glass Both sides of your stringer cut out. .. so you need/should Grind/bevel ONE repair.

Tear off your L cut and grind/bevel your repair .. make backers to lam at least a layer or two of mat .. then let that dry and regrind/bevel ( without cutting through your new layed up mat ) .. then Mat/1708 x 2/Mat.

That schedule Should reach your 1/4" ( looks more like 3/8" but whatever is needed to build up your lams ).

ONE repair .. one grind out .. One layup schedule .. one sand/fair .. prep and gel. Should be goodish as new ( as best you can make it without getting into Inside lam templates then quick coat outside bonds etc. ..

I hope Im making myself kinda understandable here .. been a long day for me ..

Any more questions just ask away.

YD.

 

[exnavyman123]

Re: How can i repair the cut out i did in the side of the stringer?

hey yacht, i think i understand just to confirm, remove all i cut and toss, make a backer on both areas and grind all around the whole area, how far to i have to grind, about 3 inches all around? then layer polyester resin i assume is what is there now and csm a layer or 2, let dry, dish that and more layers of csm and 1708 going from small pieces down first then larger. so in total we are looking at 6 layers total 1 of which is 1708. bear with me here never did this yet but that much layers seems like it would end up to be really thick. do i need a certain thickness of csm or 1708? I assume if the 6 layers of the cloth ends up to be a hair too thin the gel coat finish can compensate where the six layers is enough for the strength right?

 

[exnavyman123]

Re: How can i repair the cut out i did in the side of the stringer?

1 last question, i think, i'm hoping this area i'm repairing will end up to be strong enough, i understand the mechanical versus chemical bond thing. And i think you are to use just enough resin to saturate the cloth and thats it, also I think this whole stringer system is distributing the forces evenly and even if this area isn't quite as strong as it was that nothing catastrophic will happen. I'm just wondering under what circumstances in driving the boat will put this repaired area to the test, just driving about 40 mph and hitting very small waves on a lake?

 

[oops!]

Re: How can i repair the cut out i did in the side of the stringer?

as far as the repair failing.....if you glass it properly.....it wont.

poly resin and fiberglass can be as strong as steel...the chances of the repair failing just depends on the first bond to the substraight. but with a little care...this is unlikely to happen.

the repair area could be run just as it sits.....the only problem would be water intrusion into the open substraight. there is little stress on the fiberglass in a 4 inch patch.

the main stress areas are the trbbing of the transom to the hull....the stringer full tabbing to the hull and the deck tabbing.....so...for you ....no worries

 

[Decker83]

Re: How can i repair the cut out i did in the side of the stringer?

Just saying.
I think I said all of this in post #6. (LOL)

 

[exnavyman123]

Re: How can i repair the cut out i did in the side of the stringer?

ok, Thanks oops, just to confirm, probably the boat was constructed of Poly resin so that is what i intend to do the repair with, the resin i bought was from home depot or lowes in a rectangular can and i believe it's poly, waterproof resin or whatever, i did a lot of research on how to do the prep work. I assume when i dish the area out that if if thinnest part is very thin that's ok? Also i read the woven roving thats in two different directions is the strongest layup to use with csm on to of that, is that correct?

 

[Yacht Dr.]

Re: How can i repair the cut out i did in the side of the stringer?

the resin i bought was from home depot or lowes in a rectangular can and i believe it's poly, waterproof resin or whatever,

Be quick !! ,, all I can say about big box resins ..its GP resin .. cough ..

Is it poly ..waterproof resin or whatever .. .. . .. ?

Look into USC resins .. and glass ..

YD.

 

[exnavyman123]

Re: How can i repair the cut out i did in the side of the stringer?

Ok Yacht, i'm going to go the epoxy route rather than poly resin, using epoxy what would be the best method? Can i do the same exact thing you said in post 27 using epoxy resin?

 

[exnavyman123]

Re: How can i repair the cut out i did in the side of the stringer?

also i was going to use the pieces i cut out for the backing, i wanted to see if i could use the corner section to place back under the repair area to create a backing with a corner so i can use that for the shape in doing the layup, i assume i would need to grind all gel coat off the cut out sections or not since it is epoxy going on to gel coat then cloth on that then epoxy , etc .....

 

[exnavyman123]

Re: How can i repair the cut out i did in the side of the stringer?

ok Yacht, i got better resin, i got the 105 and 206 west system epoxy to do the repair areas, using epoxy resin, do i have to grind a large area around repair or just a few inches all the way around? Also do i have to use just 3 layers at a time to do the layup using epoxy resin?

Thanks Bud

 

[Decker83]

Re: How can i repair the cut out i did in the side of the stringer?

If you use the epoxy you need to use the right fiberglass.

Kent

 

[exnavyman123]

Re: How can i repair the cut out i did in the side of the stringer?

the fiberglass i bought is evercoat sea glass fiberglass mat, says for poly and epoxy resin, also got evercoat fiberglass cloth , not good?

 

[Decker83]

Re: How can i repair the cut out i did in the side of the stringer?

I know the matt should work fine. Not sure about the cloth. What weight cloth?

Kent

 

[exnavyman123]

Re: How can i repair the cut out i did in the side of the stringer?

not sure, its real fine square stitching like woven roving