how thick the fiberglass?

[CarMan]

I am doing a hul extention on may Bayliner 3288.

How many layers of 450g fiberglass shud i hawe in the botom?
Shud i do only in fiberglass, or samting in betwen layers of fiberglass

[apex1]

Could you be a bit more specific? How long the extension, how do you support it (lengthened girders, stringers?), do you move the transom? and so on.....

[CarMan]

of course, it's not so easy to en what inside my head.

I will only extend swimplatform, so I do not move the rudders or something (the boat has straight axles)

Swimplatform is extended 4 feet.
My boet is stern hawy, and neds 4 trimlabel full down, so i am doing an hul extention below the swimplatform, is extention is 3 feet.
i am adding 2 trimlabels to it. its the only thing how is going to be monted on it.

The boat has propeler tounels and rouder is monted on the stern, so i need to do tounels on the new extention to. the rouders is outside the tounels when fully tilted, so i can not do rounded tounels on the extention.

her i som pictures.

one of the pictures is from an boat how has somting like tis don (foundit on internet)

[apex1]

Oh, uhh ahh, hmmm, yes!
I think that will become less a question of how strong the extension, but more how well engineered!?

have a look here:
http://www.boatdesign.net/forums/surface-drives/diy-tunnel-drive-20433.html

BAECKMO !!!!

[CarMan]

I am not mowing my rouders. ther is lots of 3288 how get tis extention don, and it do good! las ster heavy and you do not need so mutch trimlabel.

i am not like schort owerhan on hte swimplatform, so i am doing the swomplatform atleast 1 feet longdet then the hul extention. I am allso doing owerhan at the sides (you can se how in the privius picture)


my questien is, how do i do the hull, is it OK to do 6 layers of 450g fiberglas?
ore shud it be 4 layers and divysel, then 3 layers abow ?

how is the orginal hul construktion?

[CarMan]

Ather boats whid this type of construktion.

[apex1]

[QUOTE=CarMan;293761]
my questien is, how do i do the hull, is it OK to do 6 layers of 450g fiberglas?
ore shud it be 4 layers and divysel, then 3 layers abow ?
/QUOTE]

I do´nt know the original laminate, maybe someone else will chime in!? Do just a solid layup, no core! if you do as the others have done (shown in the pictures you do´nt have wide sections with unsupported skin, so you do´nt need additional stiffness (and that would be the only advantage of foem core). But foam is always in risk of water intrusion, that is just another risk you do not need. 6 layers should do the job very well in my opinion. It is fabric, no mat ja? In the 4th picture that looks like mat. Use fabric, mat is just weight but has not much strength.
Do not enclose the compartment forever and eternity! Make a inspection hatch / hole.

Regards
Richard

[CarMan]

i will do 2 "doors" for storage 70x70 centemeaters eatch

[apex1]

Perfect!
and this:>>>>It is fabric, no mat ja? In the 4th picture that looks like mat<<<<??

[CarMan]

I am not sure what you say.

i think you want me to use this:
http://www.viebke.nu/komposit/matta_vav-filer/image006.jpg


not this.
http://www.viebke.nu/komposit/matta_vav-filer/image002.jpg

last year i build a rof extenton, an i only use the thinf you cald Mat, i feedl werry strong.

can i go for 2 layers of mat 2 layers of fabric and last 2 laers of mat agen ?

and use som extra layers of fabric in all courners.

[apex1]

I am not sure what you say.

[QUOTE]i think you want me to use this:
correct!

last year i build a rof extenton, an i only use the thinf you cald Mat, i feedl werry strong.
yes but that is mainly the resin the mat does not add much!

can i go for 2 layers of mat 2 layers of fabric and last 2 laers of mat agen ?
You can, but I do not recommend. Use one layer of mat outside (so, the fabric pattern will not "print through") than fabric/mat, fabric/mat, fabric, thats it. The mat between the fabric layers helps to avoid dry spots and air entrapped, but structural has not much effect.

and use som extra layers of fabric in all courners.
Thats right, make some soft corners, tabbed with cloth.

Good luck, lets have a picture when finished.

Richard

[CarMan]

the boat is sitll in water and will be for 2 month, then i can start.

[apex1]

We are patient here, enjoy your summer! Is too short anyway.

[Commuter Boats]

of course, it's not so easy to en what inside my head.

I will only extend swimplatform, so I do not move the rudders or something (the boat has straight axles)

Swimplatform is extended 4 feet.
My boet is stern hawy, and neds 4 trimlabel full down, so i am doing an hul extention below the swimplatform, is extention is 3 feet.
i am adding 2 trimlabels to it. its the only thing how is going to be monted on it.

The boat has propeler tounels and rouder is monted on the stern, so i need to do tounels on the new extention to. the rouders is outside the tounels when fully tilted, so i can not do rounded tounels on the extention.

her i som pictures.

one of the pictures is from an boat how has somting like tis don (foundit on internet)
Gentlemen, I hope you don't mind me joining in your conversation as I have a thought or two.
The obvious, making the extension the full 4 feet (or 3 feet 9 inches) of your platform would yield 33% more buoyancy with very little additional weight.
It would also be easier to board at the swim platform from a skiff if the skiff wasn't able to get under the platform as it would be if you recessed the extension by a foot.
I'm guessing from your photos that your three-foot extension would yield near 2000 pounds of buoyancy ( approximately volume 11x3x1 33 ft.³) and your structure will weigh between 3 and 4 hundred pounds... 1600 pounds additional buoyancy.
It seems that you've probably done your research and know that 3 feet works.
I agree that the unsupported square doesn't justify a core with an exception to the transom, I would core that or reduce its square by recessing the trim tab actuators.
I've done a bunch of variations but never one quite like this ( I've included a couple photos of one that I did that didn't add planing surface).
I'm a little surprised that the rudder doesn't misbehave in the examples shown.
Gerald

[CarMan]

I hawe not don anny calkulations. bur manny boat has this don, and som of them allso has ounderhulls (ounder hull, the boat has strate courners, not runded. It ad flotation to)

the boat is stern hawey, and the wxtention will help the boat to not be stern haewy.

the one i hawe talkt to say it is only goot thing to ad a awtention, but i am a litle worid aboa how it effekt turning the boat sidways (bow truster to starboard, rouders to port, starboer enging forvard, port enging back)

the extention of tonels can slow dom the water from starboard enging / thru the roder. (in may exampel)
----------------------------------

maby ai am ading a fueltank in the extention (it wold be nice to have 200 liters extra fuel)

[CarMan]

in this picture you can se the baot is stern haewy

[Commuter Boats]

On the boat pictured above, I also firmed up the bilges,"(ounder hull, the boat has strate courners, not runded. It ad flotation to)" which also had the effect of increasing planing surface and I was concerned about too much lift at the stern so I didn't increase the planing surface in the extension but had the boat wanted a little more it would've been easy to fair the extension in with the running surface of a hull.
I would not suggest that you firm up the chines on your boat as that will affect the handling.

[CarMan]

I hawe troubel tu translate this.
[[ I would not suggest that you firm up the chines on your boat as that will affect the handling ]]

It si this i an not sur abaot [[firm up the chines ]]

[Commuter Boats]

I hawe troubel tu translate this.
[[ I would not suggest that you firm up the chines on your boat as that will affect the handling ]]

It si this i an not sur abaot [[firm up the chines ]]

"ounder hull, the boat has strate courners, not runded." = firm up the chines on your boat

[CarMan]

no ounder hull on my boat, yast the extenton.

but you can se on the ater pictures, ther is boats whid ounder hull and extentions, and it works fine.

my only consunt is thet the tunnels will make the water go whid the tounls, even when rodren is curved.

[CarMan]

I hawe start the prodjekt.
this is how i do it.
let the pictures talk!

[CarMan]

her is moer pictures

[apex1]

Not bad! And sufficient access, good.

[CarMan]

i hawe ad 2 layser of wax and polich it

[CarMan]

then i ad 2 layser of wax how i not polich of

[CarMan]

and to day i goth the gelcoat on

[apex1]

Hmm, moment please. You did apply the Gelcoat on top of the non polished wax??? And now?

Is that the mould that we see here?

[CarMan]

yes i did put gelcot on top of thick layer of wax.

it is the muld in the picture

[Herman]

I hope it demolds well...

3 options:

-it demolds well. (not likely)
-it will hardly demold (likely), but you can strip the mold from the product. Luckily the mold is a one-time operation, no need to keep it intact.
-add one layer of polyester and mat to the gelcoat, strip that from the mould, add wax and polish it very carefully, and start with new gelcoat.

Please use mold release as it is intended: polished to a high gloss.

And when experimenting: Test on small panels, not on full size and critical objects.

[CarMan]

the mold is a one tim use only, and its buld to be disabeld in peasis

[apex1]

the mold is a one tim use only, and its buld to be disabeld in peasis

"Disassembled in pieces" is what I understand. You may be lucky, but as Herman said, that is´nt the best way doing it.
why did´nt you ask man? Here are dozens to assist you with pleasure. Too late anyway.

Hope you will get it off clean!

Regards
Richard

[CarMan]

last year i did extend my flybridge, like now i did a mold & i use only wax, it work thet time, oh it do this time to.

[CarMan]

finsich pictures

[apex1]

Well done!
When you need a job, let me know............
I just would say that.... but then I have seen the place where you installed the toilet................:D

[Herman]

The toilet should be installed as much to the front as feasable, preferably on front of the bowsprit. That way it will be cleaned every time you sail in rough sea. Besides that, it is as far away as possible from the "admirality". That's how it worked in the 17th century. (and if it works for them, why not for us? :) )

The extension looks very good. Well done!

One small thing that crossed my mind: Please do reinforce the new stern well enough to withstand the loads caused by the trim tabs. Loads can be surprisingly high.

[CarMan]

the hull, I thought to do in solid fiberglass, until I reach a thickness of 1 centmeters.

How das it sound. (the tunels will halp the struktion to be stady)

(not my boat in this picture)

[pasty63]

CarMan,

Nice job on the hard top. Are you going to add underhulls as well, or just extend the hull as is (soft chine)? I've considered this extension as well, as I've seen the 32xx's with them and they have a nice cruise attitude. With the 110 hinos, I don't think the underhulls will do me much good anyway, where the the hull extension would add buoyancy and storage.

If you don't mind - list out your layup schedule and materials usage when you're done. I still don't have my engines back in yet, but that's not a reason not to do a hull extension:)

[CarMan]

I am not doing the underhull, only the extention.
(i ghot the 150ph hinos)

i can do a list when i am finis. It whil take som time, the boat is 1 houer car trip away. So i can only work on it in the week ends.

[pasty63]

I understand - I also have about an hour to drive to work on my boat. Consequently - its extra slow going. I appreciate your willingness to post the information.

By the way - where in Sweden do you normally go in your boat? I spend a lot of time with relatives in Sponavik (just on the Norway border with Sweden, off the E6 north of Stromstad) - and it reminds me of where we go boating in Washington and British Columbia. With the price of fuel there though, it would be difficult for me to afford boating.

-.bryan

[CarMan]

The boat is located in Oxelösund, it is on the Swedich east coust. in the weekands w normaly go north fom oxelösund, som times only an half houer trip, and som times 2 and a half houers trip.

We do not stay in the harbur, we allways go away from the harbur and stay on a irland sor the hole weekend.

on my holyday i normaly in the boat for 4 weeks, we bo both south and north (normaly som wher betven Byxelkrok ang gävle)

[CarMan]

i hawe yast finich the last layers of glasfiber on the swomplatform.
the time is 01:40 in the night. i hawe started the heating fans to reas the tempratur in the garage.
aboat 3 aklock i am turning the fans off en go to the bed.

[apex1]

Thanks for the update!

A bit short time for good curing!?

[Herman]

I presume he cures after the construction is completed (and before painting)

[CarMan]

Now is the moment of thruth.

firts i saw the edge
teh i disambel the upper half of the mold. Tehn i nok the filer whid a hamer.
After thet i turnd it over an hamerd in a coupel of wood keals.

[apex1]

Now is the moment of thruth.

firts i saw the edge
teh i disambel the upper half of the mold. Tehn i nok the filer whid a hamer.
After thet i turnd it over an hamerd in a coupel of wood keals.

Congratulations! Lucky chap.;)

Heat it up again, for several hours! It is not fully cured at those low temperatures!

[CarMan]

i have betven 15-20 degreas celcius in the garage.

the first 5 layers did i lay last week, so i thik they are totaly harded.

[apex1]

i have betven 15-20 degreas celcius in the garage.

the first 5 layers did i lay last week, so i thik they are totaly harded.

Go above 25°C for min. 4 hours, higher temp. is even better.

At these low temperatures it can happen, that the resin does not completely cure in 3 month! Or sometimes never!
Come on spend some 67 kroner on energy.;)

Regards
Richard

[CarMan]

i will son do the doors in the swimplatform, then i will heat upp the garage for thet work and the swimplatform is still ther.

[apex1]

Sounds good.

25°C min.
4 hrs. min.
more is
better

[CarMan]

Thenks for all help so far!

One spot on the surfas looks like this, what wnet wrong here?

(i want to learn, so i dont do same mystake next time)

I can not attach the picture, i will tray later....

[CarMan]

now it works!

[apex1]

Read from my lips:

T E M P E R A T U R E ........................

[CarMan]

Do i get this gelcoat kraks if the tempratur is to low, when the gelcoat sets?
ore is it when the first layer of plastick sets?

[apex1]

I would have to ask at the yard, but I am not going there anymore this year.

Maybe Herman will answer this!? I gave him a PM

Regards
Richard

[Herman]

and there he is...

This phenomenon is called "alligatoring" or "elephant skin".

It is caused by the first layer of gelcoat not being cured properly. This can be caused by:

-temperature
-under catalisation (too little MEKP added. Check the datasheets, usually 2%)
-improper mixing
-too little cobalt added (should not be the problem, in non-tropical countries cobalt is added to gelcoats as standard)

As soon as the second layer (gelcoat or laminate) hits the first layer, the first layer cannot cope with the high styrene levels and starts to "live" causing these wrinkles.

Nothing to really worry about, but it does give you some nice hours of refairing and painting...

[apex1]

Thank you Herman!

So, our Swedish friend, go up with the temp, as I said several times now!

Regards
Richard

[CarMan]

Thenks!!!

[CarMan]

I need "doors" to my swimplatform.

[CarMan]

I will soon go out in the garage and see if i get it out of the mold.

[CarMan]

Now the children is in bed, and i hawe sow the edge and then get it out of the mold. Nise and smoth !

no damage in the gelcoat at all.

i ust 2 layers of gelcoat, 5 layers of glasfiber 20mm bonucell 3 layers of glasfiber

[apex1]

Well done Ol´Svenska!

[CarMan]

First more picture of the "doors"

[CarMan]

to day i tested how it fits on the boat. The last picture show wher the side of the new hull are going to be. (under the water i will folow the original hull, but ower the water i will go strate upp)