Transom advice needed

[RED-355]

Hi guys. i am renewing my transom on the fraser.

a few questions.

1. should i cut the floor to access the bottom of the transom and if so how far back from the inside face of the transom.

2. the existing transom seems to be 2 pieces glassed together, wouldnt just one thick piece be better??

3. someone suggested using some kind of hook to scrap out the old transom and just sliding in the new one????

i have included a few pics!!

IMG]http://i227.photobucket.com/albums/dd203/rx2now/DSCF2810.jpg[/IMG]


http://i227.photobucket.com/albums/dd203/rx2now/DSCF2814.jpg






http://i227.photobucket.com/albums/dd203/rx2now/DSCF2816.jpg







http://i227.photobucket.com/albums/dd203/rx2now/DSCF2817.jpg




http://i227.photobucket.com/albums/dd203/rx2now/DSCF2818.jpg



http://i227.photobucket.com/albums/dd203/rx2now/DSCF2819.jpg




http://i227.photobucket.com/albums/dd203/rx2now/DSCF2322.jpg



http://i227.photobucket.com/albums/dd203/rx2now/DSCF2326.jpg

[FNQCairns]

Nice looking boat, it will be a goody when you get through with it.

In answer:

1. Yes you will need to, how far will depend on how good you are at working tightly, I am not very good or tolerant of doing tight work because it often ends up to a compromise.

2. 2 is always better than 1, 3 better than 2, a sandwich is by nature when glassing very strong, also if using ply you actually end up with more individual ply laminate layers using the thinner sizes, more strength again.

3. Don't think you will keep with the hook idea, good clean and well sanded glass is the key to a good non chemical bond which is all you will get with new glass over old glass...an adhesion bond, preparation is the key.

Here is link to one I prepared earlier :)

http://www.shareaproject.com/pages/projectTut,p,28,00.html

cheers fnq

[RED-355]

ok cool.

im thinking about 300mm back from the edge!!

i want to put in those underwater lights too! so i will do these at the same time!!!

wow. thanks for the link! geez it looks great, this is my first boat - i hope i never have to do that!!!




http://i227.photobucket.com/albums/dd203/rx2now/photos131.jpg



david

[ozscott]

are you putting underwater lights off the transom mate?

Cheers

[RED-355]

yes one either side of the outboard leg i think maybe one on each side about 1 metre toward the front, but i heard they are super expensive??

[ozscott]

The good ones from the US seem very expensive - $900 plus for one in some cases!!

Cheers

PS. I wouldnt mind some cheaper but waterproof LEDs for the transom underwater...great fun for kids, attracts some fish and squid etc

[FNQCairns]

yeah 300 should work Ok IMO still there is notthat much extra work or cost in 400mm if you decide at any stage, you will also get to examine the stringers a little also, hope no surprises there:o.

Expect around 150mm or even 200mm worth of run up the inside for all your fillets, for adhesion bonds esp this is where all transom strength actually comes from, up the sides, along the bottom hull, the floor and onto the bottom of the cap.hope that makes sense.

cheers fnq

[RED-355]

i think it does, i will have to post some pics as the job progresses!!!

[gavsgonefishing]

Mate, youve gone so far with the thing, and you do not want do the transom thing again. Dont muck around with it. Cut the whole transom out and replace it with 2 x 25mm ply glassed together. I have some pics on how I did it somewhere if reqired. Like FNQ, I cant work in small places either.

I would be cutting it back 600mm, that way you can have a look at the stringers, you got heaps of room to muck around with and I would be putting up to 300mm of lapping with the glass first 600 chop 100mm, 2nd 600 triaxial 200, 3rd 600 chop 300..

Replacing the transom is not a real big job, its just got to be done slowly with a bit of thought.

Are we itchy yet??

Gav

[gavsgonefishing]

OH and I would be using some 2 pac epoxy to glue the new transom into the sides and bottom of the existing hull before laying up the glass

[rhycebullimore]

mate im doing the same thing and have mates that have done it, i would be 600 mm back...alot easier, but in saying that im also redoing the stringers and floor....please please please consider why and where you are putting those lights, any penetration in the transome is a place for water to enter and not only that i would not likr to remover any for strnght purposes...i have gone as far to only run ply down to my new floor height then solid glass to the bottem of stringer...il be running glass stringers not timber so i know i have not one nit of timber under my floor...as far as penetrations have gone the only ones im doing for my pod will be bored first...then the hole will be solid glassed then rebore the glass so it is 100 percent sealed. hope htis helps

[RED-355]

im taking one step at a time!!

i do like the idea of underwater lights they look fantastic, BUT i dont want to jeapodise the longnitivity of the new transom!! they must be sealed 100% or im not really interested. i dont want to do this job again!!

im going to cut it 600m from the inside edge now - when my business slows down for the afternoon!!!!

also someone must have a pic for mounting of these lights!! but i do like the idea of a glass transom from the floor down - but this is my first fibreglass boat so i am treading in unknown waters!!!!!!

and i am itchy!.....................

[rhycebullimore]

so am i it's one big learning curve...i am actually doning a fiberglass course first anf for 250 dollars you get to do a project...materials supplied (glass/resin and advice)...my project will actually be the transome of my boat...i have a Haines hunter 17c...from stock to scratch ill be starting againg completly transforming it to a podded center consol complete with underfloor kill tank and esky.

[gavsgonefishing]

rhyce, thats one hell of a way to start on a learning curve, good to see how you go with it, maybe start a thread from woe to go.

Its good to see some of these backyard projects come to life, I thought I was the only mad bugger (Pr!@#k). These sort of projects seem to be very time and money consuming.

Its always good for testing out the relationships with the neighbours and spouses anyway

Gav

[RED-355]

ok ,so im gonna cut 600mm back from the rear of the boat, what about the sides then?? do i just go as far as the angle grinder allows me too??

[RED-355]

ok ,more progress.

http://i227.photobucket.com/albums/dd203/rx2now/DSCF3056.jpg


someone now has told me i am doing it all wrong and i should have cut the transom out from behind, and he's a boat builder!! any thought......


so any ideas on the best way to put in the new transom i.e should i glass both sides of each 10mm marine ply then wait till it dries and glass them both together???

[dnej]

Grand Marlin, are you out there ???
David

[TJ Bear]

There are a number of ways to fix the transom. The very best way is to remove the entire transom, however you need to be very good at scarfing and fairing to get it done right.

Coming as you have from the inside is fine as long as you remove all the timber and any glass that has delaminated. It is by far the easiest way to go. Just make sure all surfaces are keyed with say 80grit on a 4" grinder then cleaned meticulously before you laminate (vacuum the entire area then wipe with an acetone rag). Thought I might dispel a mith that multiple layers of cloth such as 2 is better the 1 and 3 is better than 2. The only reason you would build a laminate in multiple passes is to prevent a high exotherm due to the mass of a heavy laminate which cause large amounts of shrinkage and even go off before you could roll air out of the laminate. When building up a laminate with multiple passes remember that if the second pass is more than 72hours after the first you have no chance of getting crosslinking of the laminates and you will be relying on a mechanical bond to prevent delamination.

If you manufacture a pannel of say 200 x 1500 out of 8 passes of 600g chopped strand matt total glass weight of 4800g it is impossible to tell where the fibre is place in respect to the direction of stress in the panel due to the random orientation of CSM, to compensate for this when using CSM you must over engineer the pannel by500% or more to ensure you don't have a failure. This is the reason you never see a racing boat either power or sail built from chopped strand mat. If you manafactured the same panel and layed it up with 2 layers of 1100 unbalanced triax of say 450 at 45dgrees / 450 at 45 degrees and 200 at 90degree and placed the high fibre count along the short axis of the panel you would have far stronger and lighter panel. You also need to consider the resin type you are using as VE has far superior elongation before breaking than poly becuse of the cured epoxy molecule that it is based upon. High resin content in the laminate will also produce a heavy laminate that has high initial stiffness but will break and fracture (low shear strength) than the exact same laminate with a low resin to glass ratio.

There is more to professional composite structure design and repair than most imagine and if they ever had to do a repair to a society standard on a comercial composite vessel they may be suprised at the science involved. There are repairs and rebuilds out there that flatly scare the shit out of me and I hope they never fail at an inappropriate time.

[RED-355]

well ok, thankyou very much for that. im sure there is much more to it than just lying down sheets and glassing over them. i must do much more research before this is done then. i dont fully understand what you mean, but i will in time.

hopefully another skill i will master.

let the fun begin!!!!!!

[dnej]

Red, if you print out the TJ Bear post, and re read it, you will get the drift of the matter.
David

[dnej]

http://www.aafibreglass.com/aa_retail_price_list_web_20061004.pdf

Red,
That link shows the Triax material,way way down the list
David

[RED-355]

ok thanks for your help guys!!

next question do you think that one 25mm thick marine ply is better than 2x 12mm glassed together???

[FNQCairns]

No as I mentioned above a sandwich containing as many ply layers as possible will be the strongest, better again will be 3 x 9mm but overall flatness might suffer...then it can become a right pain.

cheers fnq

[rhycebullimore]

i was warned by numerous boat builders as that is the thing not too do cut your transom out as you have the potential to lose the shape, mine is 50mm- 60mm thick, in order from a sanded back transome, 600 CSM, 600 CSM, wet out ply in goes first piece, 600CSM wet out ply (second piece) apply 600CSM snadwhich together,, apply clamps let it go off, don't attemp to glass the new inside of transome till you have faired and sanded where you need after transom has gone off, make sure you are using a non waxed resin or you may get delamination if you havn't sanded back befor you add onagain (ie from stringers or glassing over transom to seal)

[RED-355]

ok, this is the stage im now up to!

the transom has been sanded on the inside to remove any traces of timber.

i have cut out 3 pieces of 10mm marine ply after cutting out a cardboard template first.

do i now place one of the pieces of the marine ply on the ground flat and place a layer of mesh on it and glass the second piece of ply to it?? then jack up the front of my car and place both pieces underneath it so as to clamp both pices together??

then after it dries do the same to the third piece??

any ideas??

[RED-355]

here are some of the photos!!

[RED-355]

OK i am getting closer!!

i have an idea. if you look closely at my transom timber i have put a texta box around where the bung holes should be. (sorry photos r too big)i am thinking of cutting this section out (about 120mm x 100mm) . i would then resin in a thick piece of perspex and glass over it. this is so that when the transom is all in, then i would simple drill out the bung hole so that if anty water got in , it would simple hit the perpex rather than the timber!

this would hopefully make the transom last longer!!

the next idea is to bore a hole around where the ladder bolts would go through (25mm dia) the transom. then resin the hole up so when the transom is in i would just simple drill into the resin - not timber??

any ideas!!

its almost ready to go in.

david