boat stuck in mould

Yes, sanding sucks. Use the proper sanding materials, like for instance Mirka Abranet. I get it here: Mirka Abranet but there are more sources.

 

There's a lot to be said for visiting a place like this forum, and getting all the advice you can stand. There is I think even more value in experimenting and establishing for yourself what works and what doesn't.

Taking the word of even a well intentioned stranger is like listening to an older brother while he's reassuring you that it's perfectly safe to jump off the barn roof. That sheet tied around your neck may look like Supermans cape...and you might think you can fly...but gravity will teach you a life lesson.

Using parts of the old mold to experiment with is a good idea, but there's one significant difference between it and your plug surface. The mold has had time to cure and season leaving it almost completely free of potentially reactive agents. It's those uncured chains of polyester resin molecules that tend to stuck to the next layer if given the slightest opportunity. In other words a procedure that you find suitable on one may not give you the same results on the other.

You only need to follow a few simple rules to give yourself the best chances of a clean release. 1) A smooth polished surface helps eliminate the possibility of a mechanical bond between the two. 2) Five or six coats of wax applied over as many days builds up a decent wax barrier and is your first line of defense. 3) On any new mold surface PVA is almost an essential ingredient...the only caveat being if you're an experienced mold maker and you've done this a hundred times before...the wax might suffice. In your case stick with using PVA straight from the bottle...spray on a light mist coat followed a minute or two later by a slightly heavier application. Using your old mold to practice your spray technic is it's best possible use since it duplicates all the features found on the plug. PVA can and will run, drip, or puddle on the surface so go with two or three lighter coats instead of one heavy one. With a little practice you can get a pretty smooth PVA skin that will make this next pull a success.

MM

 

i might know why it got stuck second and third time. more testing will confirm my suspicion

 

thats the news i been waiting for !! confirm and reconfirm again know and understand why it happened so you have it locked in and wont do it again !!!!
. Its been one hell of an excise and cost a arm and a leg but in time and materials and scrafice of a mould but when you ready shear what you discovered . i must have lived a completely charmed life because i never had the pleasurable misfortune of ever having a product of my own stick up . had some really tight ones but with brute force and a load of wedging and levers has come apart . . i seen and repaired lots of other peoples mistakes and saw a whole half of a spit mould for a 33 foor motor sailer distroyed because some one used a old rag he picked up that had diesel on it and polished the plug just before it got gel coated !!!
I have always thought long and hard about every phase of the whole of the glassing thing and looked and learned what works and what didnt and why it didnt . in factories i always worked with the exsperianced guys and learned what they were about .
Keep at it !!!one day real soon the clouds will part !!

 

Up date, up date, up date ,time for up date !!!.

ok time is slipping away rather rapidly we are now into July already and 5 months till xmas and new year 2013, so whats your state of play .
You had plenty of time to completely rebuild the damaged boat sand , fair and repaint with a hard polyurethane 2 part paint and finne sand and polish to high gloss shine and remake a new mould !!, so where you at ??
what was the results of your testing ???? what did you find ???

 

slow down, money is tight with me, so boat is sanded and repaired, wont be ordering the materials till wed should get them fri, then ill be rebuilding the new mold. its gonna be very slow from now on. when the boat is repainted it will be left for ten days to make sure it had cured properly. before applying the tooling gel. achually plus seven days so seventeen days before tooling gel is on, due to a wax a day.
ok as for the testing, in one area i applied the gel coat filler and waxed it about six times. when it was time to pull it from the mold it was stuck, after giving it a good old thug it came away ripping with it the gel coat filler from the mold.
in another area i applied pva just by wetting some cloth and putting it on no added wax here. when it was time to pull it away it almost slipped off with litter or no effort whats so ever. same for the spray with no added water just pva on its own.
final thoughts. what bugged me the most about the whole ordeal was that why did the first boat release from the mold so easiely, simple answer really because the boat mold was not damaged in any way or form.
when it was time to release the boat from the mold the first time i should never have hit it with a hammer that was my mistake that cost me so dearly, in saying that i never knew not to hit it with the rubber hammer, it was what i was told from the fellow i bought the mold off of. i took his word for it and though no more about it.
once the mold was hit with the hammer the damage was done and with my little knowledge of it did not no how to go about fixing it properly. i should have came here and asked straigh away.
why did the second boat get stuck, well another easy answer. i repaired the mold using gel coat filler and it was repaired where the keel meets the stem and in one of the stringers using the filler which had no wax solution, so it was doomed to get stuck in these two places and it did badly.

so why did the third boat i built get stuck in the mold. easy answer again.
i have a new motto now, if it worked the first time why change it.
when it was time to lay up the first layer of fiberglass strand on the gel coat i changed the fiberglass from 300gsm to 450gsm it was just too heavy to apply and bubbled with plenty of air pockets. it was just too heavy for me to manage it. so then why did one side of the boat look grand compaired to the other simple again. for the side that looked well and free from defect was because i put down on roll of fiberglass cut to size on the mold and applyed the resin. on the other side that got the damage i cut out two foot my three foot strips and layed them on the boat mold and over lapped the 450 fiberglass big mistake it then became 900gsm fiberglass. i have the boat up and band stands upside down so the hull is facing the roof. and when i go under the boat and look up at the damage its all in straight lines where i doubled up the fiberglass.
now this dose not mean the other side was done right because the fiberglass did not stick to the gel coat and had to be sanded off and repaired in some places.
this is why it stuck on me because the gel coat was not attached to the fiberglass there fore when it was time for the release it was just stuck.
i remeber when i was cutting out the boat from the mold on the second one i was admiring how well the fiberglass had stuck to the gel coat so well. but there was one or two places where it did not so its extremely important to roll and roll that fiberglass into the gel coat. and by no means use a rubber hammer on a mold, trust me i know what im talking about. hope i wrote this as clear as possible. if you stare at something long enough it will tell you its problems.

 

have a million questions for you !!

ok as for the testing, in one area i applied the gel coat filler and waxed it about six times. when it was time to pull it from the mold it was stuck, after giving it a good old thug it came away ripping with it the gel coat filler from the mold.

There's never any about six times !! its six time of five times

Ok tell me about this filler you talk about !!
discribe in absolute detail what is it???
what are you using as a filler ???
Is it a mix of gel coat and something to thicken it ,plus the wax solution ???
Is it catalysed and how much catalyst do you mix with it ???
how do you apply it in the damaged areas and what do you do to it ??
sanding ,polishing, waxing ,every detail and dont leave any small detail out !!!
The filler should never come away from the mould !!! it should be well and truely stuck in the hole its filled .
Coming out is one problem !!!
sticking is another problem!!!
With just using wax alone this should never happen !!!,so something you are doing is causing the problem ,got to get to the bottom of this !!!
The filler you using sounds very suspect!!!

What sort of rags you using ?? soft materials that are slightly fluffy feel or bed sheet type materials ???. old tee shirts are pretty cool , apply the wax with sponge dampened with water well wrung out so is just damp and rub the wax round and round and all over . leave for a few minutes and then littly polish off . constantly flipping the rag over after you rubbed a few times till you have a nice shine and dont see any sign of the wax on the surface of the mould . should not make any differance it its the moulds gelcoat or the filled part should all be the same .

 

Never hit a mould !!

i am glad you have learned first hand about hammers and moulds !! NEVER HIT a mould ever with anything !!
Star cracks go right through the glass out to the gelcoat surface of the mould !!
If hit hard enough could even in bad cases damage the glass as well all the way through .
Only way to repair is to gently grind out all the marks back into the glass as the gel coat is like a egg shell and the hammer if it hit hard enough on a thin mould could have caused a soft spot shattering the resin within the glass all the way through one side to the other . !!
first signs as you grind off the gelcoat usually shows as a white marks within the glass layers , so need to get that out as well , then need to replace the damaged glass with new glass !!, when its hard sand below the surface and fill with gel coat .
Remember everything like talc and aerosil you mix with the gelcoat will kill the shine if you tru to polish it !! it will never shine like the mould was so the very last fill should be just 99% gelcoat with a couple of drops of liquid wax to seal the surface and catalyst .
On big repairs its better to do all the repairs and filling to just below the surface level then mask up the area and gently spray the whole area and build up gel coat thickness that way !!.

Repairs is a whole area of learning on its own !.

Repairs being pulled out is a mystery something is not right with what you done !!

 

What paint you goint to use ???

For boat moulds and plugs etc just about every one on this planet uses dura tech as can be seen on the picture its gets a really good shine
Left in the sun it goes so hard it is just about impossible to sand its that hard . can put almost anykind of paint over the top !! wax 6 coats and a spray of release and never ever had any kind of a problem any where i worked !!

Note not all paints are compatable with each other or compatable with the wax and specially the styrene in the gel coat .
2 pot urethanes the same auto motive is not the same as marine and theres also industrial 2 pots as well . its a mine field and you all have to do some testing of your own to find the secret combination that will work for you and what products to use and what not to use !!
You only just begining and its a looooonnnnngggg bumpy road !!. .

 

Whacker,
It sounds like you're learning your lessons...maybe the hard way, but learning them none the less.

Don't get too attached to some of your ideas concerning why it stuck. In the end it stuck because the wax wasn't sufficient to stop the hulls gelcoat layer from reacting with the patch, and your PVA coat was too thin to offer any real protection. Your own tests have proven that the wax on wax off method doesn't work, and that unthinned PVA works perfectly as a release agent.

Another lesson learned is using lighter matte to lay down your skin coat...and make sure you roll out those air bubbles! Always...always...wet out the surface BEFORE you lay down your matte. Putting resin on top of dry matte is a sure way to trap air under the matte layer. My personal preference is to wet out the surface with a heavy coat of resin...lay the precut piece of matter in position...then with a fairly dry roller press the matte down into the resin. On a skiff your size I'd wet out the next section with another heavy coat of resin and repeat the process. This gives the previous piece time to soak up some of that excess resin, and start to soften the binders that hold it all together. Now go back to your first piece and apply enough resin to finish wetting it completely. Do the same to your second piece because it should be ready by now for it's second coat of resin.

Laying up a hull is all about timing...with all your pieces precut, labeled and organized in the order they're going into the mold. You wet out an area, lay down a piece, wet out the next section, and laydown that piece. Then go back and finish wetting out the last one, and move on to the next. You're never in a hurry...just methodical. When the last piece is down and throughly wet-out...then go back and begin rolling out your air bubbles. With practice you'll eliminate most of those during your wet-out process by forcing the resin through the matte from the bottom up...which helps displace the air as the resin soaks into the matte, and applying plenty of pressure with the resin roller.

Because of all the strakes on your hull I'd want to give myself enough time to get those rib rolled before moving on. That means I'd probably lighten up on the catalyst to give myself more working time, and plan on doing it one half at a time. Remember torn matte edges are easier to lay down and keep down on a radius then a cut edge.

Best of luck
MM

 

just to add to

Wetting out glass is about getting the resin on quickly and evenly and letting it soak a couple of minutes !!
I always use a mohair roller to wet with ! it holds more resin than a brush applys resin more evenly and in bigger areas !, 90% of the bubbles have gone when you done with wetting out and is far easer to get the other very small bubbles out with the hard roller .
100 mm wide medium sleeve is easy to use and at the end of the job can squeeze the resin out and wash the roller ready for next time .
If you are doing continuous glassing keep all your gear in a plastic container that has a completely sealable lid . Acetone evaporated very quickly and if theres the slightest breeze even quicker wash you roller and make sure they work properly , as the acetone bcome saturated with resin it begin to jellefy in the bottom so get rid of it quickly as the whole lot ill go hard and you loose some things and have a massive cleaning job on your hands !!If you dont wash hard rollers properly the resin will still go hard even in acetone or mek or what ever you are using . at the end of the job you can wash all your gear in hot soapy water !! some soap powders are able to wash out semi soft acetone soaked rollers . some dosent work at all so you might have to exsperiment with differant powders till you find one that works . if you take care of you gear it will last a long time !! i have hard rollers from more than 25 years ago they are genuine Venus rollers and worth looking after are nice to use and make a good job and still in good condition . I took them apart and greased and put in storage . Even the simple mohair sleeve can be washed and hung up to dri for next time . When you look at the amount of waste you can collect at the end of each job remember everything costs you !!,so use all and waste nothing .
Be Carefull lowering you catalyst ratio on the first layer of glass , Personaly i wouldnt advise at all ,just do smaller areas and finish each one and move on to the next styrene attack you havent had yet that i have seen . so that could happen !! Know what your gel time is always!! know that !! its very important .
Did you pick up about really wetting the gelcoat first and putting the glass on top !! its easyer to bring resin up from under the glass than try and push it down through from the top !!

 

Tunnels,
I guess you and I are never going to be in complete agreement on everything, and that's OK.

When it comes to glassing I have to respect the time you've put in and your experience, but when it comes to first timers, small scale shops and guys working in their backyards some of your advice may not apply.

Let me give you an example...You advocate using Mohair roller covers for your wet out work, and then cleaning these rather expensive covers in order to save them for the next job. On the surface this may sound like good advice, but in the real world this often isn't practical.

In my situation it makes more sense to use disposable covers and discard them after each use then it does to foul up gallons of acetone trying to save a roller cover that will probably be too stiff to use the next time I need it anyway. Today acetone is just too expensive to buy and ship, so I treat it like a valuable resource. That means used covers are discarded and the acetone is only used to clean cages and rib rollers...this cuts down on the gunk in the bottom of my acetone buckets and keeps the rest of my tools cleaner.

Because my acetone is relatively clean it also means I can clean a rib roller by simply swooshing it around in the bucket for a few seconds and hang it up on the edge to dry.

I can't even believe you suggested using hot soapy water!

When I advised Whacker to slow down on the catalyst I didn't mean to the point where he might have problems...I only meant that with all of the rib rolling that he's going to be doing that he doesn't want the resin flashing off before he's done. That means don't use hot batches...stay out of direct sunlight, and plan on doing one half at a time. If it were me I'd probably tear most of my material into strips to make working all those ribs and strakes easier to lay-up, but he's not me.

Give the guy a break he's doing this out of his own pocket...he can't just uncork a fresh barrel of resin whenever he wants to, and he probably can't afford to burn up a couple gallons of acetone trying to save roller cover.

MM

 

Each to there own !

ok ok i know what you saying ! rolled covers in your part of the world may be really cheap but most places i worked and even in nz they get to be exspensive . A company i worked at the end of each day all our gear we used hot soapy water not all soaps are compatable when you find th right one its amazing how good it works .next morning everything is dry and just like brand new
Hang rollers on the side of a bucket so all the crap is at the bottom all the time . between 4 guys we were allowed 1 litre each day to use so you get used to working very cleanly and wisely .
Tahiti acetone was liquid gold so being used to working with almost nothing i was quite used to it . they used a hand cleaner to wash there gear in and also some sort of french engine cleaner when they could get it .
At home i did the same ,all containers had air tight lids 2/3 of my work i did in my garage so used the same gear over and over many times .brushs are the hardest thing to clean properly !. You can squeeze almost all the resin out of a roller so theres very little to polute your acetone . Each to there own !!. Mek i cant stand the smell of just about makes me throw up the inflateable company used it to clean off there adhesives and the tubes before glueing .

 

Question !

When you bought the mould from ???? it had been used obviously !! what wax was he using for his boats !!! did you ever ask ??

 

no i cleaned the mold using acetone before applying my wax. ive put it to bed tunnels, im happy with my results from testing. concentrating on my new mold now.