hull extension in progress with pics

[oops!]

Re: hull extension in progress with picks

Re: hull extension in progress with picks

today was supposed to be a major layup day...but some things got in the way.....i didnt get on the boat till 745 pm....since i did some glassing two days ago....and kicked over a bucket of resin....i had some grinding to do


first i ground out the spilled resin, ......then with the grinder i rough and scuffed the sections to be glassed........ then acetoned them, every things gotta be clean

i wasnt totally happy with the area around the strakes and chines as the fiberglass tended to form air bubbles there.....so it was time to mix up more gype...(peanut butter)

im using glass balloons for beanut butter......remember when mixing...use your breathing mask

i wanted the peanut butter to be a little thiner so i could actually pour it in the needed areas.

it was mixed to a cosistency of soft ice cream.....uasually its just a bit thicker.....you can thicken it just by adding more glass bubbles

with my trusty bucket i spread the gype.
the mixture was literally poured in the strake areas.
since the mixture is thicker than resin..it doesnt immeadately want to cling to the the area....so you have to press the first bit in so it goes into the scuffs previously made by the grinder. after it grabbed..(not kicked)..it was then screeded (like you screed concrete) to level. and then it naturally flowed flat smooth

the mixture was literally poured in the strake areas then screeded in...(like you screed concrete.....the top layer then flowed to flat smooth
while i was wating for the gype to kick...i cut the glass for the layup

 

[oops!]

Re: hull extension in progress with picks

Re: hull extension in progress with picks

each peice of glass is custom fit to its specific area

the area being glassed is now at a four inch over lap from the last layer of glass.....thats why each peice of glass is custom fitted into place

after pressing the drivers side glass into place and checking the fit....i removed it and mixed up some resin.....i applied the resin to the hull and repalced the glass panel
due to the gype i placed earlyer... the glass lay up went perfect.....
very few air bubbles...i got them all out with a paint roller......

thats when murphy showed up.......
it was 1:15 in the morning....i poured the resin into the gallon bucket..then grabbed the catelist and poured about a quarter of the big bottle into the gallon of resin........i thought ...oops...you schmuck..whattya doin. ...

being just a bit smarter than your average sack of hammerhandles...i knew it would be stupid to use that batch of super hot resin....so i pitched it out...

when i went to pour the next gallon of resin...i was short of resin by a quarter of a gallon ....disgusted with my self ...i locked up and went home!

 

[oops!]

Re: hull extension in progress with picks

Re: hull extension in progress with picks

capn jason was refering earlier to the resin fiberglass mixture......

i posted this in open forum...but that will soon disappear.... so im going to re post it here for future reference

if you are glassing a layup...and you have a bit of resin left over...you might want to pour it on the fresh glass...right..?...cant hurt..little more resin just makes it stronger......

it doesnt...it weakens it.

fiberglassing is a chemical forumula.....it must be the right amount of glass to resin...mat or cloth..........
the rule of thumb is...

totally saturate the fibers with resin...no more...no less......

this is some resin that was left in a bucket and removed the next day

a perfect plate sized chunk of resin with no fiberglass in it

bout a quarter inch thick...strong...!!!!

i snapped this with my bare hands...it shattered like peanut brittle.....

even if there was fiber glass in the resin ...it would still be prone to shatter.

you can hit a good layup (with the proper mixture) with a hammer...and you wont break it

on the other hand...if you dont use enough resin...the layup will be weak....not brittle...weak...

if mixed correctly....fiberglass can be as strong as steel.

allways remember..the rule of thumb...

totally saturate the glass....no more...no less

 

[Capt. Mike]

Re: hull extension in progress with picks

Re: hull extension in progress with picks

so will you have her back together by may


www.bigwoodboat.com

 

[oops!]

Re: hull extension in progress with picks

Re: hull extension in progress with picks

not if murphy keeps showing up!....

i figure im a week and a half behind schedule....i want the stringers/transom in buy the end of the month....that way i can start fabricating the cap...the new back end, the seats and dash.....paint is scheduled for mid april...then engine ...upholstery...last week in april

 

[Robj]

Re: hull extension in progress with picks

Re: hull extension in progress with picks

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.

Since this hull is old, there will be no chemincal bond between the old glass and the new. The only bond will be mechanical, which makes it even more important to do your prep work. You want that mechanical bond to be as strong as as possible. That is why grinding and cleaning is so important, as is increasing the overlap between old and new to give it more surface area for the glass to bond to.

Have a great day,

Rob.

 

[Robj]

Re: hull extension in progress with picks

Re: hull extension in progress with picks

Oops, another note what are you mixing your resin at? How long is it taking to kick? The way that piece shattered, just wondering if you are mixing it too hot? I know it has no strength without the glass, but you made it look too easy. My guidline was 8 ml hardener per litre of resin, which is about 1% hardener by weight, good at a temp of 70 degrees F. I went as low as 6-7ml per litre in the summer.

I hope you are not getting your materials from the place you got your balloons from. If you are, you are paying too much.

Have a great day,

Rob.

 

[jcsercsa]

Re: hull extension in progress with picks

Re: hull extension in progress with picks

Since this hull is old, there will be no chemincal bond between the old glass and the new. The only bond will be mechanical, which makes it even more important to do your prep work. You want that mechanical bond to be as strong as as possible. That is why grinding and cleaning is so important, as is increasing the overlap between old and new to give it more surface area for the glass to bond to.

Have a great day,

Rob.

ok how come there are thousands of people out there have done there transoms with resin and they get a chemincal bond , dont they ??? so whats the difference here??? John

 

[oops!]

Re: hull extension in progress with picks

Re: hull extension in progress with picks

Oops, another note what are you mixing your resin at? How long is it taking to kick? The way that piece shattered, just wondering if you are mixing it too hot? I know it has no strength without the glass, but you made it look too easy. My guidline was 8 ml hardener per litre of resin, which is about 1% hardener by weight, good at a temp of 70 degrees F. I went as low as 6-7ml per litre in the summer.

I hope you are not getting your materials from the place you got your balloons from. If you are, you are paying too much.

Have a great day,

Rob.

actually i used two hands to break it...i just held the peices so the camers didnt get a shot of shards on the ground...

im mixing cold....2 capfulls of cat, to just under a gallon.....a little white rona bucket.......ive gotta mix cooler so i can work the big peices of cloth

and im paying way too much for materials.. i like to keep the money local....but vancouver is local enough......

cheers....gotta go to sleep now...been up all night
oops

 

[ondarvr]

Re: hull extension in progress with picks

Re: hull extension in progress with picks

People hear and read things online about polyester resin, epoxy and types of glass, much of it has a grain of truth, but many times it gets blown out of proportion.

Yes, once the resin has cured you get less of a chemical bond and more of a mechanical bond, but there are still reactive sites in the old layup (resin) to bond with. The mechanical bond, while not quite as strong, is not weak and will take a great deal of abuse. You test the bond in the lab by pulling it apart, if it's been prepped well and the bond is good, glass fibers will be torn from each surface, which is common. Sometimes it doesn't separate along the new bond, it may be deeper into the old section or new one, it may also be a combination of the two. If you did a poor job of prep, or if the surface was contaminated for some reason, then the bond may (will) be poor and it may pull apart easily with little or no fiber sticking to each surface.

The most common cause for the line of thought that polyester doesn't bond to anything, is people doing a repair with little or no prep work, sometimes not even cleaning off the old dirt and gunk, then using cloth as the first layer. This type of repair will fail almost immediately and then the resin is blamed. For the best results use a grinder with 36 grit or coarser paper and keep the surface clean.

Epoxy does bond better, the problem is, you still have polyester under it, so if you exceed the stress level the polyester substrate can handle, the epoxy layup will still pull right off, only with some of the polyester still stuck to it. It's almost like the polyester to polyester test, except all of the failure is in the polyester substrate this time.

Mat is used to build bulk and sort of help with the bond. If you use cloth or roving as the first layer, there is a resin rich layer between the glass and substrate, this resin rich layer is weak, just like the casting oops! made. Add glass fiber to it and it becomes strong, this is the roll of the mat, the fibers in the mat are random and will fill the area that cloth and roving won't. Now when stressed there is glass near the surface of the substrate, not just resin, so it will not fail like a cloth only layup will. The bond is actually the same, it's just that the resin isn't failing near the bond line now.

Epoxy is much stronger, so this resin rich area at the bond line is not as likely to fail when only cloth is used.

Mat has the lowest strength of the typical types of glass on the market, it's not weak and may add strength and stiffness (don't confuse stiffness with strength), but other types of glass do a better job at adding strength for the same weight. Cloth works well for some things, but I rarely use it and most boat builders don't use it either, as the cost is high for the strength it adds. Roving is strong and is less costly than most other types of fabric, plus it's very easy to work with, so it gets used a great deal. Biaxial type products are very strong and add the least amount of weight and cost more, much of the time they come with a thin layer of mat stitched to them for better bonding and to help hold the resin in place.

There are also two types of glass E and S, E is the most common and is what you will find most of the time. S is stronger and costs more, to buy it you normally need to special order it. When it comes to other high end types of fibers like carbon or Kevlar, use epoxy, they don't work well with polyesters.

Not all polyester resins are of the same quality and neither are epoxies and it can be very difficult to know what you are buying. I'm not an epoxy guy, so I won't give information on it because it may not be accurate.

Polyester boats normally have a skin layer on the hull of a better grade of resin, it may be a straight VE, a VE-DCPD blend, or a straight ISO. This is a thin layer near the gel coat for better water resistance, this layer is commonly chopped, but it may be hand layed with mat. The rest of the hull and deck are normally made with an ORTHO-DCPD blend, it's not as strong or water restant, but costs much less.

What you buy in the store is normally a straight ORTHO, because DCPD's and the blends with it added, have a shorter shelf life and they need a long shelf life for the retail market. You can get ISO and VE resin, but you normally need to go to a fiberglass supply store and ask for them, they will cost more. The VE will be stronger, more water resistant and bond better than ISO, which in turn is better than ORTHO, that leaves DCPD's at the bottom, but they do offer very good surface profile because they shrink less than the other types. Straight DCPD's aren't used that often, they're typically blended with one of the other resins, to lower the cost and help reduce the shrink.

For a typical repair anything but a straight DCPD works well, and you won't be able to buy it, so don't worry about it. Boat builders assemble the entire boat with these standard polyester products, some are chemical bonds and some are mechanical bonds, rarely do they fail. The larger the boat, the more mechanical bonds there are because of the length of time it takes to build them.

Always check to see how the resin and /or gel coat is supposed to be used, does it have wax added, if it has wax in it you need to apply the next layer before the first one gets hard, if it gets hard you need sand and clean the surface very well before applying the next layer. What catalyst % is recommended, what do they say about about adding other things to it. Don't over or under catalyze and always measure it, don't add large amounts of anything to thin them, when you add more than about 5% it can start to have negative affects. Stir well after adding anything, not just a couple swipes with a stick or brush.

While it is important to use good products when doing a repair, it's more important that you use good methods and do it correctly.

 

[oops!]

Re: hull extension in progress with picks

Re: hull extension in progress with picks

man it took me 4 months of investigating, just to learn SOME of what ondarvr just wrote in 20 mins........

now thats why this site is great.

thanks for the time and knowlage. its really apprecated.


cheers
oops

 

[jcsercsa]

Re: hull extension in progress with picks

Re: hull extension in progress with picks

man it took me 4 months of investigating, just to learn SOME of what ondarvr just wrote in 20 mins........

now thats why this site is great.

thanks for the time and knowlage. its really apprecated.


cheers
oops

what OOOPs just said ,thanks ondarvr John

 

[JustJason]

Re: hull extension in progress with picks

Re: hull extension in progress with picks

Ooops,

I found the article. It was in boating magazine FEB 08 issue. The manufactor was Baja that did the testing. basically what they were looking for were weak spots but more importanly hinge points.
Given enough stress everything has a hinge point.
Lets say your plowing through waves/wakes. After the bow goes up, and starts to come back down, water wants to push the bow back up. The *** end however.... wants to keep coming down. So someplace inbetween the bow and the stern is going to be a hinge point... on every boat.

stay clean and blow out those prefilters (and tools) once in a while....
Jason

 

[oops!]

Re: hull extension in progress with picks

Re: hull extension in progress with picks

thanks capn....

ill look up thoes articals.....did they say anything about the stringers/frame providing structural stregnth thru the hinge points?

and man...i grinded for 2 hours and glassed for 4 hours tonight...about 90 sq feet of 28 oz cloth...no air bubbles allowed.....my filters must be clogged...cause my head is spinning

oh well...back atter tommorow i hope...shes starting to feel strong under foot...just a few more layers to go.......then well call the coast gaurd

cheers bud
oops

 

[redfury]

Re: hull extension in progress with picks

Re: hull extension in progress with picks

oops!, I'm truly impressed with the scope of your project and drive to get it done. I'm hoping to find that enthusiasm and self motivation to really get going on replacing my stringers and getting all that glass work done. I'm really going to work hard to educate myself ( more like indoctrinate ) on the various intricacies of working with fiberglass. The process seems straightforward, but the devil is in the details.

 

[SgtMaj]

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[oops!]

Re: hull extension in progress with picks

Re: hull extension in progress with picks

hey sarg....the heating up thing...

is caused by a chemical reaction to the hardner/catylist

try this.....get a small paper cup and pour in some resin.....add six drops or catylist...and stir well with a popsicle stick.........

wait 5 mins.....if it doesnt start to smoke...it will feel warm.....

 

[Robj]

Re: hull extension in progress with picks

Re: hull extension in progress with picks

But also, fresh poly resin (and correct me if I'm wrong, because I might be), will eventually dissolve old poly resin, won't it? So as long as the old poly is in contact with wet resin long enough, it will form a chemical bond, right?

Nope, just a mechanical bond. That is why it is so important to grind it to roughen it up so the new resin will have something to bite into.

That is what I supposed to be the case anyway, which is why the first layer of resin that I applied to the old surface on my project boat, wasn't mixed with hardener (just straight resin from the can) which I let sit for an hour or two, then I laid out the glass, and wetted it out with hardener-mixed resin.

I sure would not do it. May be able to get away with it for a non-structural area, but definitely would not do it for stringer, transom or floors.

By the way, people keep talking about poly resin heating up when mixed with hardener... is it supposed to? Mine hasn't at all.

Because if you are just glassing a layer, the heat may not be that noticable. If you put on a few layers, you should be able to feel it. The resin/catalyst is an exothermic reaction, meaning heat is created. Do as Oops suggested, it will definitely get hot.


Have a great day,

Rob.

 

[JustJason]

Re: hull extension in progress with picks

Re: hull extension in progress with picks

I mixed up a batch of about a quart soooo hot one day (building car stereo stuff... not a boat) it gelled in about 45 seconds, it was to hot to touch in a minute. I threw it on the ground and laughed at it. Then i spit on it and it sizzled. So then i grabbed a glass of water and poured it on it... the water was vaporizing as i poured it on. Then I grabbed my IR pyrometer.
315 Degrees....

 

[oops!]

Re: hull extension in progress with picks

Re: hull extension in progress with picks

the stuff is wild....

i was really tired the other night ......poured a gallon of resin...the grabbed the catylist and poured in a ton......a 1/4 of a bottle........

when i realized what i was doing....i ran it out to a snow bank and poured it all over the snow.....didnt want a bote fire.