us composites the cheapest Poly resin???

[Phish555]

Re: us composites the cheapest Poly resin???

Ok guys, Im confused. Here are a few pics of my project. Long story short, had the boat since Feb of this year. Engine mounts were soft, causing coupler to break due to mis alignment. Dug into it, rotten stringers, floor, and transom. cut away the rot all the way to good wood. Now I need to do some lay up, and finish glassing. Is there one resin that will work for both that won't cost an arm and a leg? What is the stuff at WM, and will it work for me. I found mat and cloth at auto parts, but was reluctant to buy their resin. It was a bondo product.

Here are a few pics.
http://i306.photobucket.com/albums/nn264/phish555/boat repairs/IMG_2299.jpg

http://i306.photobucket.com/albums/nn264/phish555/boat repairs/IMG_2296.jpg

http://i306.photobucket.com/albums/nn264/phish555/boat repairs/IMG_2297.jpg

http://i306.photobucket.com/albums/nn264/phish555/boat repairs/IMG_2298.jpg


Thanks in advance.
Boat is an 88 Fabuglass Jamacian runabout, 19', with a 4.3 mercruiser alpha 1

 

[oops!]

Re: us composites the cheapest Poly resin???

phish....

start a thread !

look for a local glass distributer in the phone book......

they are around.....

the stuff at wallmart is good and will work... but...wow man...huge dollars...

poly is cheap and will work....people here will say epoxy.....its your choice.

 

[seven up]

Re: us composites the cheapest Poly resin???

Epoxies have some very good properties, but also have their issues for production work, Like BillP said "the technicalities.." of polyester are what makes it so much easier to use in most situations than epoxy. Polyester can be adjusted for ease of use in many ways that epoxy can't, this makes it very user friendly when compared to epoxy. This is also part of the problem, it can be used incorrectly and still work fairly well, so people assume that if it got hard, everything is OK. Many times this results in less than satisfactory repairs and when they fail, all fingers point to the resin. Epoxies tend to be used a little more correctly, they normally come as a kit with directions for that exact formula and people tend to follow the directions closer.

While there are situations where epoxy is a much better product for the job, for the most part, the type of repairs discussed in this forum are easily handled by polyester. It comes down to what the person wants to use, it's not really a right or wrong issue and a good argument can be made for using either product.

Beautiful sales pitch.

Now if you can make it stick to wood like

epoxy you'd be a millionaire.



Enjoy

 

[oops!]

Re: us composites the cheapest Poly resin???

btw......if your doing transom, floor and stringers......your a long way from glassing......it will take over 20 gallons of resin....yup...it will.....you may as well buy shares in in wallmart if you want to go that route.

the stuff the sell is for quick small patches....

and also.....EVERYTHING has to come out of your boat

 

[Coors]

Re: us composites the cheapest Poly resin???

can we make this a stickey....

har har har yuk yuk the hee!....

ok back to the thread now...

Epoxy, and choice of slow, medium, fast= easier; stronger, and easy clean up..hehe.

 

[oops!]

Re: us composites the cheapest Poly resin???

Beautiful sales pitch.

Now if you can make it stick to wood like

epoxy you'd be a millionaire.



Enjoy

seven......poly sticks to allmost everything....even when you dont want it to...

the key is to have the surface clean....(just like in everything)....
people say that poly is garbage...because it wouldnt stick...what the problem was...is their work in prepping the surface was garbage.....

as far as sticking to wood.....the wood must be dry or forget it...even with epoxy.....

when i tore the 40 year old wood outta my poly boat...the wood failed before the poly.......if the poly doesnt stick....why the heck do we need grinders with 24 grit to get it off?....and when we are grinding we still pull out wood slivers where the wood failed not the poly

drew mitch is wading in grinder dust because he had to grind the poly out.
if it was so weak and wouldnt stick...he just could have ripped it off with his hands

i dare anyone here to try a test on poly with two coats of glass on a dry...properly prepped wood surface......the wood will fail before the poly does......simple as that....thats why YOUR boat is made of the stuff.

the question isnt weither poly is better than epoxy or vice versa....the question is what do you want to use on your polyester boat. and that is a personal choice. the factors are cost, ease of use, and what do you like better.

stregnth isnt really an issue, because our little 20 footers with 200 hp motors wont ever need the stregnth that epoxy gives....companies are building 30 foot offshore racers with stepped hulls and triple 505 racing engines outta poly....and no failures

 

[oops!]

Re: us composites the cheapest Poly resin???

seven......that reads a lot harsher than it was ment to be...

 

[Phish555]

Re: us composites the cheapest Poly resin???

btw......if your doing transom, floor and stringers......your a long way from glassing......it will take over 20 gallons of resin....yup...it will.....you may as well buy shares in in wallmart if you want to go that route.

the stuff the sell is for quick small patches....

and also.....EVERYTHING has to come out of your boat

oops, is that response ment for me? My repair area isn't that large, pretty much my engine compartment area. Transom area measures about 40" wide by 17 tall. 2 stringers on each side to a length of about 40" as well. Flooring between stringers.
Why does "EVERYTHING" need to come out of the boat?
Thanks,

 

[ondarvr]

Re: us composites the cheapest Poly resin???

Bonding with wood is one of the things that epoxy excels at, that's why it's what needs to be used when glassing over a wooden boat, I would never recommend a polyester for that use.

The other part of it is that because polyester costs so much less and is so much easier to use, the boat building industry is based on it.

If we were discussing high end, go fast, custom made, mega $$$$ performance boats that are engineered to take advantage of what epoxy can do with fibers other than glass, then yes, epoxy would be the resin of choice.

In this forum most people are replacing stringers and transoms in 14 to 21' boats with 25 to 150hp, most in the smaller size and lower HP range.
These boats don't even come close to exceeding what a polyester resin can handle, so it really doesn't make that big of a difference which product is used. That's why I say it's not a right or wrong issue, just a choice that needs to be made by the person doing the job.

Even if all these boats were made with epoxy to begin with, the wood would still need to be replaced due to water getting in because of poor workmanship or design, which is the same reason it rotted away with polyester.

 

[oops!]

Re: us composites the cheapest Poly resin???

oops, is that response ment for me? My repair area isn't that large, pretty much my engine compartment area. Transom area measures about 40" wide by 17 tall. 2 stringers on each side to a length of about 40" as well. Flooring between stringers.
Why does "EVERYTHING" need to come out of the boat?
Thanks,

yes it was meant for you.....

bud....i hate to tell you this......but if the transom is rotten...the stringers are showing signs of rot......

your foam is soaked...and you might need to replace/repair the stringers, the whole legnth of the boat......and replace the foam......

what you want to repair....are "indicators" of a much worse problem.

take your boat to a self weigh station and weigh it....subtract the weight of the trailer and other things...that will give you the weight of the hull...if your 100 lbs over...you need to take core samples of the foam

time to start reading on the forum....big time

 

[Phish555]

Re: us composites the cheapest Poly resin???

Hi again opps. Like I said, I am up to dry wood every where. I posted some pics, were you able to look at them? I could do that weight thing, if I knew what my boat is supposed to weigh.

PS. No wet foam. It was all dry. And from what I have read, I don't even need the foam. It came out like pieces to a jigsaw puzzle. I have all of it though. Isn't the foam more for holding pieces in place when the boat was manufactured?

 

[oops!]

Re: us composites the cheapest Poly resin???

Hi again opps. Like I said, I am up to dry wood every where. I posted some pics, were you able to look at them? I could do that weight thing, if I knew what my boat is supposed to weigh.

PS. No wet foam. It was all dry. And from what I have read, I don't even need the foam. It came out like pieces to a jigsaw puzzle. I have all of it though. Isn't the foam more for holding pieces in place when the boat was manufactured?

i saw the pics on this thread.......

the weight of the hull is avalible from the manufacturer....it might even be on the vin plate......

how did you test for dry foam...did you take core samples?....and how many from where?

the foam is a little structural...but under 20 feet the uscg says it must be on the craft....and wet foam rots boats.......thats why we are trying to use alternatives....

http://forums.iboats.com/showthread.php?t=233479

the foam is there to keep the boat a float if it sinks.....so the survivors have somthing to hang on to after abandoning the ship.

i really hope you caught it in time...but i would investigate fully...knowing the total extent of the rot before doing a repair...or your back in there in 2 years


(ps....you should really start a thread on this one)

 

[BillP]

Re: us composites the cheapest Poly resin???

Billp

What you're refering to is the cure profile (it can go by other names but this term is easy) and it's determined by the promoter package, base resin and fillers if used. The promoter package can be adjusted for a rapid gel time, or a long one, rapid would be 12 minutes or less, slow would be 25 minutes or longer, (this is a general time range) this is at 77F. The second part of the cure is the gel to peak, this is the time between when it gels to when it reaches it's highest temperature. Each can be adjusted for the type of part being made, thin smaller parts typically use a short gel time and a fairly quick gel to peak, thicker and larger parts tend to be made with longer gel times and longer gel to peaks. This longer gel to peak helps to keep the peak temperature lower in the thick areas. These specs can be adjusted so the type of part being made cures correctly.

There are also several different types of catalysts that can be used alone or blended with each other to fine tune it even further and allow one resin to do several different things well by just switching between types or blends.

Isotropic and orthotropic are properties of a subtsance refering to it's strength in different directions, they could refer to a cured FRP composite, but not in the way we're discussing.

Thixotropic refers to how a liquid can change it's viscosity when agitated or sheared. This can be adjusted for each use also.

Orthophthalic and Isophthalic are types of resin, with ISO being the stronger one.

I listed these because they are very similar terms, but have different meanings.

If you never discussed any of this with a resin rep, then you either never talked with one, or you never brought it up, as these are the basics.

I think I mentioned already that these terms were lost in dead brain cells a long time ago...but don't confuse my lack of tech savy of definitions with lack of experience and skill in the trade. Glassing isn't as simple as reading text off spec sheets so let me clarify your mis-interpretation of what I said about talking with resin reps. Sure they know the "basics" but usually had never personally glassed enough to know jack about the "trade secrets" of glassing...other than what they were told by glassers. They only know the basics of how their products apply to individual trades. IE...What was important to handcrafted surfboard and small fragile parts glassers was (and still is) never a high topic of interest in production boatbuilding.

Here's an example of the resin rep who never discusses certain issues that glassers discuss. The rep says too much styrene weakens the resin. The glassers ask how much strength is lost at what ratios? When tasked for specific data his reply sidesteps the question and somewhere in the discussion he quotes his company chemists as saying the info might be around somewhere but nobody ever asked before. The rep can't back his "knowledge" with engineering data from a spec sheet that shows strength vs styrene ratios. End of it all is the data is never given because the rep never likely talked with customers who exceeded the suggested ratios. In reality, the practice of drastically over catalyzing for a hot fill coat (for sanding) is (and has been since the beginning of poly boards in the 1950s) done on 99% of every poly surfboad made...and no problems. How many resin reps know this? Boat mfgs do similar overcatalyzing for different reasons and it never shows up as an inferior product. How many reps know it? The answer is very frigging few. I have other examples but won't go there.

bp

 

[BillP]

Re: us composites the cheapest Poly resin???

i just cant imagine being a good enough glasser to have a kick time within 15 seconds of hands off.....

especially with the nuances of a hand layup, ....wow

It's done everyday in every shop on the planet that makes poly surfboards...or course there are always exceptions but it's industry standard in that trade. Those who don't track and use data for production either have more glass jobs gone bad or don't need to dial in times so tight. Log all data from every glass job you do and start watching how easy it gets to establish work and kick times.

bp

 

[ondarvr]

Re: us composites the cheapest Poly resin???

I listed the terms so they would be used accurately and I agree, it would be difficult to remember them if it wasn't something you were working with frequently.

You never asked me about styrene content weakening the resin, but I did give you the answer on that, about 3% in most products, more than that and you start to see a difference. What you asked about was catalyst % weakening it and at what % it would reduce it's strength at each percent over the recommended amount. I told you we don't track it that way and why, if you read any of the information I offered you, or talked with the chemists I offered to put you in touch with, they could have better answered your question this subject.

And as I said before, what's common, or standard practice as you say, in an industry, is not always the correct or best way to do it. Each section of the market has this type of misconception or mis-use of a product(s), they're what lead to problems, or products that aren't as good as they could be. Any good manufacturer will use the products they buy as recommended by the supplier, each one has been tested in the way it is designed to be used and over catalyzing is not a recommended practice.

Maybe you need to watch "Holmes on Homes", it's a Canadian TV show. Mike Holmes goes to peoples houses and repairs what "people in the industry" thought was the right way to do a job. These are large and small contractors, some have been around a very long time. The problem is the people (contractors) thought they were doing the job correctly (some are just a rip off), but they don't use the materials as recommended, so the results are poor and frequently dangerous. Some of what these contractors do will sort of work and may last a while, and this may be the way they always use the products. But when the right product is chosen for the job and is used correctly, the finished product comes out much better.

 

[oops!]

Re: us composites the cheapest Poly resin???

small fragile parts

bp

what small fragile part is there that needs to be glassed ?(in any glass application)

btw...im really getting a lesson here.....

ive been very consistant in my mixing, and temps, ill drop the temp to add kick time to an area, or when it just doesnt go right......bit fifteen seconds...wow....the closest ive got was 5 minits...and that was by mistake
(ill start keeping track, on pen and paper as youve suggested)

but ive also over catylised.....and it was super, brittle

cheers
oops

 

[BillP]

Re: us composites the cheapest Poly resin???

I listed the terms so they would be used accurately and I agree, it would be difficult to remember them if it wasn't something you were working with frequently.

You never asked me about styrene content weakening the resin, but I did give you the answer on that, about 3% in most products, more than that and you start to see a difference. What you asked about was catalyst % weakening it and at what % it would reduce it's strength at each percent over the recommended amount. I told you we don't track it that way and why, if you read any of the information I offered you, or talked with the chemists I offered to put you in touch with, they could have better answered your question this subject.

And as I said before, what's common, or standard practice as you say, in an industry, is not always the correct or best way to do it. Each section of the market has this type of misconception or mis-use of a product(s), they're what lead to problems, or products that aren't as good as they could be. Any good manufacturer will use the products they buy as recommended by the supplier, each one has been tested in the way it is designed to be used and over catalyzing is not a recommended practice.

Maybe you need to watch "Holmes on Homes", it's a Canadian TV show. Mike Holmes goes to peoples houses and repairs what "people in the industry" thought was the right way to do a job. These are large and small contractors, some have been around a very long time. The problem is the people (contractors) thought they were doing the job correctly (some are just a rip off), but they don't use the materials as recommended, so the results are poor and frequently dangerous. Some of what these contractors do will sort of work and may last a while, and this may be the way they always use the products. But when the right product is chosen for the job and is used correctly, the finished product comes out much better.

Maybe you need to watch your customers instead of TV?

"We don't track it that way" basically means you CAN'T provide hard engineering data to back up product "spec" claims. Phone calls to chemists are hearsay...published engineering data gives credibility. I asked (many, many, many times) about OVER 3% so please represent my questions accurately.

For what I do and for what 99.99% of the home project guys here need there is no reason to know all the tech specs. This is a buy off the self at retail group and thixotropic, orthotropic, etc mean little to nothing to most. The only reason I know it is from glassing (which was at surf shops and boat factories, etc). My interest here is to have resin that doesn't gell in a month of sitting in my shop. I don't believe it's a serious problem either because there is too much time between the factory and retailers. I'm in constant contact with all of the above and nobody is complaining about it. Although quoting spec sheets can be very inspirational, they can at times also be in the baffling with bx category to many.

So, what you keep harping about is a "resin spec" only view of glassing with zero acknowledgement to the fact that mfgs have been falling "outside" of the specs since the beginning of time...and that they know how to do it without ill problems popping up later or inferior products, yada, yada, yada. Thinking that inferior products automatically happen because a mfg busted the specs is a utopian state of mind that doesn't exist. If you can't give engineering data that measures how inferior it is, how are you proving it? Maybe "proving" is only to those who don't ask?

It takes a little tempering (some need more exposure than others?) in the trade to understand where and why specs are successfully busted. I gave one example of hot fill coats on surfboards...which typically uses 40cc catalyst per pint+- of poly laminating resin. The resin kicks fast enough to stop drips while in motion before hitting the floor and aprox 45 seconds from mix to kicked. 90% of the coat is sanded off...the remaining 10% presents no inferiority. The life of the product is fully met/exceeded with best cost to the customer. Also, with addition to exceeding 3% catalyst, another 25cc of liquid wax (Mod C in my neighborhood) is added to the batch. For sure it's out of Mod C spec like the catalyst and again...NO problems, now or later...at least not in boards that are still around after 50 yrs. So why not use finishing resin for a sanding coat? Because it's too expensive and/or doesn't do a better job. It's a proven method that has plenty of success to back it. Why is this method still happening after 50+ yrs in the industry? Because no resin rep has been able to prove a better and more cost effective way...it isn't because the "industry" has "mis-conceptions". There are other trade tricks with catalyst AND styrene that show zero defect issues too but I'm not going there.

bp

 

[BillP]

Re: us composites the cheapest Poly resin???

what small fragile part is there that needs to be glassed ?(in any glass application)

btw...im really getting a lesson here.....

ive been very consistant in my mixing, and temps, ill drop the temp to add kick time to an area, or when it just doesnt go right......bit fifteen seconds...wow....the closest ive got was 5 minits...and that was by mistake
(ill start keeping track, on pen and paper as youve suggested)

but ive also over catylised.....and it was super, brittle

cheers
oops

Measuring and logging data removes guesswork later. Practice makes perfect.

So what media was it "brittle"? How did you measure "brittle"? Sitting mixed in a cup or in layers of glass? What oz glass and how many layers...and how much res to catalyst? Did you compare the brittle ratio mix with a standard ratio mix? It takes a massive amount of over catalyzing to physically tell (without measuring devices) when a single layer of 10oz cloth is brittle from over catalyzing.

If you want to do empiracle tests on resin, pour small cubes, layups etc and destruct with a hammer, crush in a vice, etc. That's what I do to see what happens. It gives a little non tech insite to different materials...structural epoxy vs 5 minute wallyworld epoxy is a good example and it's a giant spread.

Let me re-phrase "fragile"...in a glasser's eye it would be a "delicate" glassing job where a single layer of lightweight cloth needs to wrap around and stay "tacked down" without lifting and/or leaving bare spots at small intersections in the covering. Products I've worked on that follow this suit: surfboards, rc boat hulls/decks, rc plane wings, fire combat backpacks, auto/van spoilers, repro antiques, exp aircraft instrument panels.

bp

 

[oops!]

Re: us composites the cheapest Poly resin???

Measuring and logging data removes guesswork later. Practice makes perfect.


If you want to do empiracle tests on resin, pour small cubes, layups etc and destruct with a hammer, crush in a vice, etc. That's what I do to see what happens.

bp

heh heh heh.....

resin three inches thic dropped from mid chest height ....no glass....stuff left in a bucket. that was mixed too hot to use. (it cured allmost black)
when i drop simelar castings.....they break in 3 to 4 chunks....the hot mix, shattered in about ten chunks....that is why i say the "hot" mix was brittle.
(btw...i make sure it lands flat,,,not on an edge)...or i cant count the results...as they are flawed.....he he he ...thats my "lab"

ive now dropped about 8 castings of different mixes.....(im courious)

with my "low tec" experiments...i can only come to the conclusion that a really hot mix would be a brittle lay up.......this would not be noticed over a large impact area or a wash area...(such as a hull plaining thry the water) but would be noticed on a sharp "rap" type of impact.....like a hitting a dock corner......im guessing this is one possible reason for crazing.

 

[oops!]

Re: us composites the cheapest Poly resin???

btw..the hot mix was 3 capfuls of cat to 2 leiters of resin....i dont know the exact amount of a cap full.....but it is a constant device for me to measure with......ive now mixed. 8, 5 gallon pails this way...so im getting better at "dialing it in"