hull extension in progress with pics

Status
Not open for further replies.

JustJason

Vice Admiral
Joined
Aug 27, 2007
Messages
5,319
Re: hull extension in progress with picks

Re: hull extension in progress with picks

Oooops...
I know I chimed in earlier about the hull not being necessarily seaworthy. I'd like to take a minute to finish up on that comment. I know you said you've put alot of research into it, and i'd like to congradulate you for having a very big set of balls, because this is something most people wouldn't try.

Here are some of the issues I see that you may or may not already know. My main goal here in writing this is not to "1 up you" or "prove my knowledge", but rather to make sure all my fellow boaters are safe.

i'll start with this.
There are so many types of resin, and so many grades within those types. With your boat being 40 years old you'll never truelly know what type and grade was used. (can you tell the difference between a polyester and vinylester layup?? I can't). The older boats weren't build with CAD, very few used presses, or vacuum bagging, and there was very little math was involved. It was more seat of the pants type job, much like the one you are partaking in now.

You know that (or have found out) that you can't put polyester over epoxy. But you can put epoxy over polyester with good bonding. You also can't put polyester over vinylester, but vinylester over polyester is still very good. Polyester over polyester is structurally the weakest bond. I know that your original hull isn't epoxy... but how do you know it's not vinylester?

Another problem with everything fiberglass. Is it does absorb microscopic amounts of water. 40+ years of who knows what, the hull will never be dry. As a rule of thumb, new poly work does not stick well to old poly work.

When they built the boat they probably had a specific thickness for the layup, and it would have went something like this.

Transom, 1 1/2 inches of marine ply + 5mil of mat on outside + 3 mil of mat inside
Keel, 7 mil's mat glass, stem to stern
Pad, 8 mil's glass
Gunwale, 6mil mat
Top deck, 4 mil non load bearing, 6 mil load bearing....

The point is, your boat, every parameter was built around an XX foot length for a runabout style of the times. But now your adding length to XX feet. Even if your work was dead on perfect using the best products, tools, and techniques... The rest of the boat may not be able to handle the extra weight, load, and leverage. The boat may break, but not on your work, but in front of your work.

Speaking of fiberglass grades. Where are you getting your glass? The stuff at home depot and autoparts stores is junk for construction, it's only good for finishing. If you haven't already. Get a gallon from the home store and get a gallon from a supplier, it's almost like working with 2 completely different products.

Another thing that I see in your construction is your glass choice. Your using this mat/weave hybrid. In construction work you should only use mat. weave is for finnish work. And similar to plywood construction, you should use alot of thin layers instead of 2 or 3 thick layers. The other thing you need to take into consideration is the glass itself between the mat. If the layer of glass infused mat in 2mils, but you have a 1 mil layer of pure hardened glass inbetween the next layup of mat, it's not going to bond well.
There are a bunch of reasons to vacuum bag and mold press, and each have their own advantages and disadvantages, but eithe route is better than hand laying. When hand laying you tend to use a whole lot of extra resin to get saturation, but to much saturation is no good. Ideally you would lay a layer, vac or press it. When it cures up you roughen up to surface to almost rip some of the top weave out. then lay up another layer of mat. The nice thing about mat is is that it's omnidirectional, and you can lay the sheets whatever way you want to.

Yet another issue is see is where you actually decided to do the "stretch". Your placing the weakest material of the boat under where the motor is going to be. It doesn't matter if you go sterndrive or inboard, the motor is going to sit on top of your work. On top of that, it's the last 1/3 of the boat that gets 90% of the stress put on it while underway. I know you talked about overlapping the layers. But overlap doesn't mean a thing on a 40 year old boat. The new matting sould run 100% over the old. When the boat was built, the hull was built in vey long layers of full length mat., not 6 inches of overlap here and there.

anyways that's all for now... i'm tired. I'm sure there will be more to follow at a later date.

happy boating oops.
Jason
 

oops!

Supreme Mariner
Joined
Oct 18, 2007
Messages
12,932
Re: hull extension in progress with picks

Re: hull extension in progress with picks

awesome post capt...really good.....lots of facts and lots of info....

My main goal here in writing this is...to make sure all my fellow boaters are safe.

you have made lots of points so ill try to respond to them all.......
but as an over view........5 different professionals in varing feilds have visually inspected the boat/hull and said i was good to go........

the captain in charge of the boat is responcible for all the souls on board...no one wants to make a rash mistake that could cause lives.

first of all ....a marine sureveyor was brought in to inspect the bare hull....to be more precise...to inspect the glass to make sure it was god enough to hold up......he said..."i can only tell you that the glass hull is currently sound".you will need an expert in fiberglass to confirm if the hull will take the new glass"

enter fizel.....the glass expert that made all safaras molds...and is currently on contract to build boats for safarah.....he visually inspected the hull and said "no problem"...."shes good"

....no point in doin all this work if the boat is gonna fall apart eh?

fizel confirmed what searay said...its poly chopped construction no vinylester...its a 69...and most boats in that year were all poly..... a few layers if woven may have been used...but he didnt see a cross section of the cut hull..... i think its all chopper gun.......

we discussed the extension...and a plan was devised as how to do the layup and with what overlap......but in typical oops fashion... in gonna over build...

as far as your very correct statment about glass absorbing microscopic amounts of water.....
nothing can be done about this.....ive dryed the boat (bare hull) best as i can , for months... however i do not beleive it will be a siginifant problem...(at least one that can cause catastrophic falure)...
the proof in this is....
.many people have made exterior glass repairs using less knowlage than i and their repairs have not failed....even my first repair of the rear corner of the transom held up for years....it just looked ugly :eek:


as for the point of hull glass thickness vs legnth....i really think searays 25 foot was the same glass thickness...the keel was a little thicker...but that mostly depended on the kid workin the chopper gun....
any way ...in oops fashion...the whole boat will be totaly glass reinforced...its allready scuffed...when the strings go in...and when there glassed in....ittl get another layer or two....thus making sure the whole vessel is re glassed stem to stern
yup shes gonna be heavy.

and btw...the glass and resin...suplies were purchased from a local wholesaler.

of the whole responce you wrote. i only disagree with one statment....
........"in construction you should only use matt"......

matt...or csm (chopped strand matt) as its known. is fantastic for forming as it tends to go around corners nicely if used in lighter qualities...ie 1 oz and oz 1/2 ....however it does not have the longitudnal strength that woven cloth does...there for, layers are used with csm and woven in a sandwich type layup...... this will be far superior than just a csm by it self in any weight.

the cloth i am using is a 24 oz with many layers of chopped/woven togeather.
the only difference is it takes less layup to acheve the same results....and it is stronger due to the type of weave.
i am still however using csm between layers ...just for the fun of it...

btw...i didnt under stand what you meant when you were talking about thickness of the glass between the the layers of matt.....you may have been tired...the matt is glass..... and the resin is what is between the individual strands if glass...it is the mixture that gives strength.....too much of one and.....:eek:

the final point you make is one that i struggled with the most.....the cut and weight transfer is directily on the plaining /surface contact point...............in other words when the boat is plaining... the full weight of the hull is on the extension area...as well as the water surface contact point is directly on the extension...at 60 0r 70 mph it better be good!
this is standard thinking...and its what i thought too...but it is incorrect.

in standard boat building..in and outboard situation....the stringers are attatched to the transom..... the pressure of foward thrust is transfered thru the transom to the stringers and finally distributed thru the fiberglass. when the bow rises to achieve a plain...it is not the glass that abosrbes the weight of the hull....the whole thing works in concert....weight is again transfered thru the transom to the stringers....now the full weight of the bow lift is on the stringers and transom...not the glass.
in an inboard situation it is allmost the same however the motor mounts are attached to the stringers and the stringers to the tramsom...but again when getting up on plane...the full weight of the motor/and bow is on the stringers not the glass.......kinda like an old front engine dragster doin a wheelie away from the line...the stress is on the frame.
hence...5 stringers

the exterior layer of the extension will be reinforced and the interior thru the strings/ motor area...will be all one peice of cloth/ with matt underlay
with the stringers attatched to the hull and the hull having a new layer of glass..and that all attached to the transom.......the only thing that really will see major stress is the surface contact point.....and that will be stronger than the old hull.......

i hope this answeres some of your concerns...and that other i boaters can learn from our points.

cheers
oops
 

oops!

Supreme Mariner
Joined
Oct 18, 2007
Messages
12,932
Re: hull extension in progress with picks

Re: hull extension in progress with picks

I've got poly resin all over my workshop and I'm getting tired of sticking to everything I come in contact with. :D

man i got long curly hair....when i was younger peter frampton had hair exactally like mine......

i got resin in it.....:(:(...its matted in the back....im either gonna have to wash my hair in acetone or im gonna have to cut it.....:eek:

i use a five inch grinder...rips up what ever you want......that sander will take you forever.......

cheers
oops
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,468
Re: hull extension in progress with picks

Re: hull extension in progress with picks

no one wants to make a rash mistake that could cause lives.
Ayuh,......
In My Younger Days,......
I used to Really Worry about that,... Every Friday,+ Saturday Night,.....:D

of the whole responce you wrote. i only disagree with one statment....
........"in construction you should only use matt"......

Ayuh,...... I Agree completely with This,.....
Mat gives a Good Bond, but the Strength is from the Cloth.....
I was slightly involved with an Airboat building operation years ago,.... They used the Same fabric that Oops is using,...Along with several other different grades,+ weights of Fabric,.....
The Mat is a Great vechicle to cause the resins to build,+ hold things together,... But it's still the heavier Fabrics that provide the Strengths....
'ell,... Even a chopper gun is shooting chunks of Glass to go with the light fibers of the Matting.....
By the way what tool do you use to grind with? I'll need to do some more serious grinding here shortly and could definately stand to get something better to do it with than my mouse sander... yeah, definately has to be something better out there.
Ayuh,..... It's pretty hard to Beat a 4" Grinder,+ several different discs for it......
If you're looking to Really Remove some material,... A disc for cutting,+ grinding Steel works Great,....
If you're just roughing up an area,.... A Flap disc does a 'ell of a Job....
Btw,..... Those Cheapy imported Grinders are a Good investment for Fiberglass work,......
You won't feel near as Bad when it $h!ts from the Dust, as you would if it was a $100.+ Grinder......
I Know,....... I've Smoked a few Dewalts before.....
 

ondarvr

Supreme Mariner
Joined
Apr 6, 2005
Messages
11,527
Re: hull extension in progress with picks

Re: hull extension in progress with picks

To keep this response short, it appears that oops! is doing it correctly.
 

erikgreen

Captain
Joined
Jan 8, 2007
Messages
3,105
Re: hull extension in progress with picks

Re: hull extension in progress with picks

I'm no expert on glass strengths, but I have been doing quite a bit of reading on the net.

If you check out a lot of the posts on the bateau.com boat site, they recommend the biaxial fabric (1208, 12 oz cloth with 8 oz. mat, the cloth at a 45 degree angle) for most projects. If you're buying from them they even will give you a layup schedule for your repair project. They have some nice boat designs too if you want to scratch build.

All the reading I've done reinforces my understanding that mat is great for helping adhesion of coarser fabrics and roving, and that it does give some strength bonuses due to the fact that the fibers go every direction, not just 1 or 2. But mat should never be used alone unless you're going for low strength + cheap. Use alternating layers of cloth and mat for most layups, to get optimum strength.

I wouldn't attempt what Oops is doing using poly in any case, since it doesn't develop a strong enough bond for my taste unless you work wet on wet, but he has a bunch of experts involve, so I'm sure the work will come out.

And it's great he's documenting it for us so well :)

Erik
 

Robj

Lieutenant
Joined
Mar 22, 2007
Messages
1,441
Re: hull extension in progress with picks

Re: hull extension in progress with picks

I think another thing you need to consider is that the longitudinal strength will come from the stringers and floor. Oops you have said in a previous post that you are beefing up the stringers to account for this. They will in a sense be the backbone of the boat. When you add the deck, you have created an I beam type structure. Should be plenty stong to account for the joint and the increased length. So I think Jasons comment on this has been dealt with.

Have a great day,

Rob.
 

oops!

Supreme Mariner
Joined
Oct 18, 2007
Messages
12,932
Re: hull extension in progress with picks

Re: hull extension in progress with picks

ok ....here we go.......

first of all.......

capt jasons comments were for the safety of all i boaters.....
he is a respected member of this community with very valid concerns.....

and capt j....you just keep on commenting..!..your views are valid...and welcomed......!...:)

imagine...if i was a new..boater...and i had a hole in the hull...i duct tape'ed cardboard over the hole and tremco tremclad'ed it...............and called it good enough...!...he would have saved my life....and ....in fact....he has made me want to build it even stronger

this is an iboats boat....and with thoes concerns from a member.......construction was HALTED.......

now.......with the general approval of the i boats members.....

(i dont want to betray anyones trust...but........imho.......there is some really heavy hitters here........and their input...... is greatly appreaceated....thank you)

i got back on her tonight....:)

btw erik.....i am trying for a chemical bond as much as i can...however...some times it is unavoidable.......
but if you read up...ondarivr said...."i wouldnt worry about it too much"

next post comin soon....(sorry for the spelling...its almost three am here...and im stoned on glass fumes!.....again:eek:)
 

oops!

Supreme Mariner
Joined
Oct 18, 2007
Messages
12,932
Re: hull extension in progress with picks

Re: hull extension in progress with picks

my buddie rob just brought up a very good point that i think every ones missing.......it was posted in that really long thread......

its really tacky to quote myself, but.....this is for future iboaters...not me


in standard boat building..in and outboard situation....the stringers are attatched to the transom..... the pressure of foward thrust is transfered thru the transom to the stringers and finally distributed thru the fiberglass. when the bow rises to achieve a plain...it is not the glass that abosrbes the weight of the hull....the whole thing works in concert....weight is again transfered thru the transom to the stringers....now the full weight of the bow lift is on the stringers and transom...not the glass.
in an inboard situation it is allmost the same however the motor mounts are attached to the stringers and the stringers to the tramsom...but again when getting up on plane...the full weight of the motor/and bow is on the stringers not the glass.......kinda like an old front engine dragster doin a wheelie away from the line...the stress is on the frame.
hence...5 stringers/QUOTE]
 

Robj

Lieutenant
Joined
Mar 22, 2007
Messages
1,441
Re: hull extension in progress with picks

Re: hull extension in progress with picks

I'm not sure why Jason hates the poly so much, but I've never known it not to stick to something... even if it doesn't have a clean surface. In fact, if Jason knows how to get poly to not stick to something, I'd like to know, because I've got poly resin all over my workshop and I'm getting tired of sticking to everything I come in contact with. :D

You are talking about two different things. Sure poly will stick to everything, but sticking and a mechanical bond are two different things. I have removed fibreglass that was not properly prepped, and it was not that difficult. Sure it stuck, but it really had no strength. That is why you have to do your prep work, grinding and cleaning, grinding and cleaning, more cleaning, and even more cleaning, to make sure you get the best mechanical bond possible, because it is part of the structure. If you just glass over old without proper prep work, it will definitely fail.

Have a great day,

Rob.
 

Tail_Gunner

Admiral
Joined
Jan 13, 2006
Messages
6,237
Re: hull extension in progress with picks

Re: hull extension in progress with picks

Fanatastic posting going on here,probably the most indepth information i have seen to date on contruction and the use of different type's or resin and all the possible ramification's. Look's like your extension was very well researched, thought out and executed....now all ya need to do is use 9lb foam highly compressed .........opp's.........;)

Just a Opinion your mileage may vary...
 

oops!

Supreme Mariner
Joined
Oct 18, 2007
Messages
12,932
Re: hull extension in progress with picks

Re: hull extension in progress with picks

jumped back in the boat and started glassing some more.....

this session.....the plan was to re inforce the joint points with more matt.
and get ready for a big lay up on sunday.....

after that acetone was applied and the glass was cut for the layup.

picbroup11003.jpg


i pre fitted all the glass....and mixed the resin.....i wanted a little hotter mix for the lay up because with the five foot extension section....its very hard to get room to work.

picbroup11007.jpg


all the stress joint areas were re matted....again

picbroup11006.jpg


in glassing the extension section....during a full lay up...all the peices are large....11 foot long sections......x 3...........that means its too far to lean over when your saturating the glass......and its allmost impossible to remove tiny air bubbles with a 6 foot long extension handle.......

as said before.....this is a hull section so air bubbles cannot be in the glass....zero tolerance.

picbroup11008.jpg


and then that jerk murphy showed up again.......with a little hotter mix...i had to rush as the layup was a lot of individual peices.......rushing just enough to kick over the resin bucket.......

picbroup11009-1.jpg


all over the drill...just missed the grinder......and right into the greshly ground keel!.....

as you know resin by itself is very weak.....so the dumped stuff all has to be ground out....oh joy..!

if any one happens to see that murphy guy.......you know ...the the guy that made murphys law?............just shoot that sucker.....

im going to try to get on it today but there is a hockey game tonight .....our rookie sensation might be back in the lineup.

tommorow is a major layup day...so by monday...i hope to finish the interior of the extension and pull the molds...

cheers
oops
 

Robj

Lieutenant
Joined
Mar 22, 2007
Messages
1,441
Re: hull extension in progress with picks

Re: hull extension in progress with picks

Looks great!! The only thing I would do is on the next round, overlap the new fabric onto the existing hull a little more. Just to make the joint a little stronger.

Have a great day,

Rob.
 

oops!

Supreme Mariner
Joined
Oct 18, 2007
Messages
12,932
Re: hull extension in progress with picks

Re: hull extension in progress with picks

ya rob thats just the matt for a little more stregnth.....

when i do the big lay ups thats when ill continue with the overlaps

the last interior layer...is going to overlap up on the transom area.....18 inches fresh contact with the layers underneath at 4-5 inch overlap....

now for more grinding...oh joy

cheers bud :)
 

Robj

Lieutenant
Joined
Mar 22, 2007
Messages
1,441
Re: hull extension in progress with picks

Re: hull extension in progress with picks

Stagger the overlap, increasing it with each layer. Don't you just love that grinding?? The perfect excuse to keep you out of the wife's hair.

Have a great day,

Rob.
 

oops!

Supreme Mariner
Joined
Oct 18, 2007
Messages
12,932
Re: hull extension in progress with picks

Re: hull extension in progress with picks

too funny
 
Last edited:

JustJason

Vice Admiral
Joined
Aug 27, 2007
Messages
5,319
Re: hull extension in progress with picks

Re: hull extension in progress with picks

Whew... the woman is gone and i have a chance to write!

Ok... first i'll comment on the rebuttles.

SgtMaj said:
I'm not sure why Jason hates the poly so much

I don't hate it at all. Boats have been sucessfully built for 50 years using polyester resin. The point I was trying to make is that the hull is built using a chemical process. The materials were very similar 50 years ago but still not the same. When you take into account the age of the original structure. Trying to adhere new poly to old poly won't always work the way you hope it will. Especially when your laying it by hand. Hand laying is always the last choice in between vacuum bagging and pressing.

oops! said:
btw...i didnt under stand what you meant when you were talking about thickness of the glass between the the layers of matt.....you may have been tired...the matt is glass..... and the resin is what is between the individual strands if glass...it is the mixture that gives strength.....too much of one and.....

Okay... what i mean't is this.
Think of a ham sandwich. The 2 pieces of bread are pressed or vac bagged resined mat. The ham is all of the extra resin that didn't get pressed or sucked out. When constructing with fiberglass you want as much bread on bread as possible... with little or no ham. The ham itself (glass) has no strength. The strength is in the glassed bread. If there is to much ham the next piece of bread won't stick to the first.

oops! said:
the final point you make is one that i struggled with the most.....the cut and weight transfer is directily on the plaining /surface contact point...............in other words when the boat is plaining... the full weight of the hull is on the extension area...as well as the water surface contact point is directly on the extension...at 60 0r 70 mph it better be good!
this is standard thinking...and its what i thought too...but it is incorrect.
in standard boat building..in and outboard situation....the stringers are attatched to the transom..... the pressure of foward thrust is transfered thru the transom to the stringers and finally distributed thru the fiberglass. when the bow rises to achieve a plain...it is not the glass that abosrbes the weight of the hull....the whole thing works in concert....weight is again transfered thru the transom to the stringers....now the full weight of the bow lift is on the stringers and transom...not the glass.
in an inboard situation it is allmost the same however the motor mounts are attached to the stringers and the stringers to the tramsom...but again when getting up on plane...the full weight of the motor/and bow is on the stringers not the glass.......kinda like an old front engine dragster doin a wheelie away from the line...the stress is on the frame.
hence...5 stringers

I disagree with ya on this one. I looked for a few but couldn't find it. But a boating magazine did an article this past month about a major boat manufactorer who hooked up all of these sensors on a new hull and ran it to find the stress points. I'll find it when i can. Point is, is that even the manufactorer had unexpected results.
For me, it all starts and ends in the glass. I look at it this way. If your smashing through waves/wakes. The drive is pushing on the transom, which is glass at first. But more importantly the water is pushing on the hull. There are 2 different forces at work. The force of the drive pushing the boat. And the force of the water, resisting the the foward motion of the boat. At the same time that resistance is pushing up on the boat, causing the boat to plane.
The way I get it, is your right in the point that the whole structure works in harmony. But the water hits the glass first, and the floorwork second.

bond-o said:
Mat gives a Good Bond, but the Strength is from the Cloth.....

Hmmm... i've always understood it to be different. Mat, (and chop because it's similar) is strong because it's layers are not geometric. Weave is geometric. If you glass a board with weave, you can tear the weave right off because it's layers are not intertwined. Because mat (or chop) is not geometric it is inherently stronger, and will not tear off the wood.
I've always thought of weave as a finnish layer, not a structural layer.

I'm not trying to start a flame war here. Part of how I think is as an owner. If oops came to me with his project and wanted to pay me a million bucks to do it, I still would not. I'd be afraid of it breaking. What if the hull lasts for 3 years and breaks on the 4th. I'd be somewhat liable in court and just don't want to deal with that.

I hope oops gets his boat done and has years of enjoyment from it. It's just that I would not personally do to a customers boat what oops has partaken in.

As far as the hull breaking or not breaking. I don't know. It either will or it won't. there are so many consideration. i just hope oops has fun with his project and doesn't sink. I'm no expert but i've done more than my share of glass work.

Keep us all posted Oops!!!!!!!!!
 

oops!

Supreme Mariner
Joined
Oct 18, 2007
Messages
12,932
Re: hull extension in progress with picks

Re: hull extension in progress with picks

hey cap..:)
glad ya wrote back...

in gonna do another segment tonight on some stuff you just wrote about..
but i wanna answer you first.....

ok...the ham sandwich thing.......again your right....glassing is a chemical process...and it must have the right ingredients for it to work...too much glass and its weak.....too much resin and its brittle as peanut brittle....i got picks about this and im gonna add them in this thread...and start another thread in open forum, cause its soooooo important to get it right.....

second...about structure......please ...please....pllleeeease....find that article....the info i gave was given to me, by a dozen naval archetechs on another site.....your comments..."unexpected results".....made my hair stand on end....i can make the extension area as strong as i want...and reinforce the joints...add stringers...but ...........:eek:

as far as the choped vs cloth....

....mabe ondarvr will drop by and give an answer....

as far as warranty issues......i understand where you are coming from...i own a store myself.....if i have total hull failure...and live :eek:...other i boaters can learn from my mistakes...it will just cost me the old hull my time and some money......lets hope bondo-s cooler and duct tape trick holds!

i can only say it has been done with sucess many times before....i just hope i get the formula right....

cheers
oops
 

oops!

Supreme Mariner
Joined
Oct 18, 2007
Messages
12,932
Re: hull extension in progress with picks

Re: hull extension in progress with picks

i was replying to a thread earlier today...

a fellow iboater was doing some fiberglass grinding without a mask..
he said "i allmost coughed up a lung"
i thought i would post some pictures of minimun safety equipment in this thread....
once fiberglass dust enters your lungs...it will never ever break down...never.
proper safety equipment is a must...fiber glass resin, has toxic fumes...as you know...you can pass out cold if you get too much fumes....

even if your working out doors you must still wear the safety equipment.

a breathing resporator that totally fits around your nose and mouth is mandatory....

thoes little paper fiber doctors type masks..will not work...even if you think they do...

picgroup12002.jpg


a good seal around your nose and mouth are paramount

picgroup12003.jpg


its obvious that the goggles should be worn when grinding and sanding...but also when pouring or mixing resin....it splashes.....got a few drops on my lens tonight....would hate to think what would have happende if i wasnt wearing them...
 
Last edited:
Status
Not open for further replies.
Top