please advise on making a male mold?

Discussion in 'Fiberglass and Composite Boat Building' started by tugboat, Aug 10, 2013.

  1. tugboat

    tugboat Previous Member

    hey guys

    today I talked to Dave Sintes and Bill Seemann and asked them -since they work with this all the time. About the costs /time /benefits to VBI vs. hand lay-up ...

    I actually was surprised to hear their answers.
    to paraphrase Bill- (and I was surprised at this) He stated basically that they do all kinds of infusion and for all kinds of projects from aerospace to marine. and he suggested it would be better to do a hand layup for my application. he has seen all my renderings and cutouts etc. and has a very good idea of what I'm up against. in fact what he said was- "resin infusion is better because it makes a lighter weight laminate.
    but for someone starting out i'd need a LOT of practice and then there was the tools. so he suggested the extra weight would in fact be better since it was a displacement hull anyway. I agree with this although I do understand the clamping effect of atm pressure is going to make for a stronger laminate the difference should be relatively negligible if done properly, for my intended use.
    Dave Sintes actually said the same thing. But furthermore- he stated he did not use the casting resin. instead he uses ordinary iso or v-ester. he was great to talk to and was very helpful. I am ordering his 4 hour vid on laying up the c-flex. And will likely use a iso for my hull..

    I appreciate everyone's advice here;

    and although an infused or bagged laminate is a superior layup...,

    I'd prefer a satisfactory hull done with a process that I fully "get"...and does not involve prior practice and the possibility of screwing it up-even if its easy for beginner...its still a learning curve involving time and materials I'm not willing to invest in.

    Seemann points out that they have tried
    c-flex hulls using the infusion process and that its almost impossible to get it to work as well as to stop air leaks due to the nature of the hull material. special mods would need to be done.
    so for the above reasons..." I'm out". (on the infusion process)

    Groper and Samsam -- you have given me great ideas. The c-flex being one.

    thanks to all... I hope you don't take it as a rejection of what are good ideas, I just have to look at it from my needs and it doesn't fit them at this point in time...hopefully I will still be able to get good advice further on in the project...such as deck to hull joints etc.:)
  2. michael pierzga
    Joined: Dec 2008
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    michael pierzga Senior Member

    Ask your sources if a Professional is avaible to supervise an infusion.

    Remember, you will be purchasing thousads of dollars worth of extra thousand for profesional onsite infusion supervision is money well spent.

    The reason boatbuilders use infusion is that it saves labour, money and produces a better laminate.

    Your reason for using infusion..labour..your significant.

    Dont underestimate how much work a wet laminate is.
  3. tugboat

    tugboat Previous Member

    Michael its great idea on paper.

    but are there actually people who would do this??

    in my area- I can state with near certainty that there are no boat builders doing this.

    in fact - the only production builders of any kind in any material reside in Toronto.-which is about 5 hours from here by car. Its not like the U.S. or the Uk or Aus. or even the Netherlands, where there are many pro builders pretty much at every marina or port.

    in fact there are no pro builders at all doing this here in Ontario that I know of(of course I could be wrong)...but in my area- (and think Siberia-like) there s nothing.

    so its a logistical problem-even so- if it would cost me a thousand for the help- and 1000 in supplies--I think ill save the 2000.00 and use it to buy better resin...
    even a hand layup will be faster than steel-save for the fairing- but its a workboat so a showroom finish sorta makes it redundant. I expect it will take me a day to do a hand layup if I have three people working on it, and its cold, and I under catalyze the resin slightly. as well I would have all my materials and implements, pre-measured resin hardener ready to go. The trick I think is organization -which makes a hand-lay up work- but I've never done it sooo..wth do I know?
  4. michael pierzga
    Joined: Dec 2008
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    michael pierzga Senior Member

    I dont know. I live in a boatbuilding region. Specialists are everywhere.

    Many times when I do a project, I call in a specialist. These people are refered to me by the technical representitive of the products that I use. Purchasing thier time is expensive per hour, but the amount of hours that they need to be on site..on my project.. are small.

    Ask your supplier.

    Hand layup is OK. Very much work for a single hander.

    Remember..with infusion the laminate surface is ready for secondary bonding after cure. Wet layup requires messy surface prep for each secondary bond.
  5. groper
    Joined: Jun 2011
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    groper Senior Member

    He can still use peel ply with a wet layup - although with an unwaxed poly resin, the surface stays tacky and can be overlaminated without prep. The final layer will need wax added so it tacks off.

    Tug, no way will you be able do this wet layup in a single day...

    Your layup shedule consisted of about 10 layers IIRC? thats 10 times the entire surface area of your hull... its alot of work mate - dont underestimate it, it will take several days with 3 helpers... by yourself, id reckon 1 day for each layer so about 10 days...

    There is noone doing infusion where i live either- all the pro builders still do the old school wet layup or chopper gun thing... change seems to be a slow process...

    If you feel that infusion is above your head, then no problem and forget it. If you do feel its within your capacity to learn it, then all i can say is its definately worth doing. These days, i dread wet laminating anything - i always end up finding a way to infuse it as it just ends up better in terms of time spent.

    Yes infusion can have the advatage of a thinner, more compacted laminate of higher quality, but thats not the reason i suggested it for you - you dont really need these qualities for your type of solid glass hull. The reason i suggested it, was because of the very thick, multi layer laminate will take you about 10 times the labour to get it done compared to infusing it - thats the main reason i suggested it for you.

    If you learn to do it, you will also be able to make perfectly fair panels on a flat table mold - which is great for your pilot house or other simple curvature areas. No fairing required on these - think of the time youll save on that... Less material, less time, less fairing, you get the idea... spend a few days to think about it...

    This is the inside of my tunnel in my cat, infused flat panel raw from the table, its covered in a bit of dust, but look at the reflections... how much fairing do you think i have ahead of me?

  6. tugboat

    tugboat Previous Member

    Groper- I see your point- that's one sweet looking hull! I absolutely agree with you on the work being 10 times as much. I WILL use peel ply too! the laminate schedule is 3 layers of biax 24 ounces on the outer laminate- then same 3 layers inside. - csm is used for bonding.
    the traditional method is to use WR mat and csm but -you might find this harder to believe- the csm and biax cloth is actually CHEAPER than the standard WR and csm. I sent a copy of Noah's website to Mr. Seemann. he was quite surprised to see the biax being less expensive...the csm for example is 4.00 per running yard -and the WR is like 3.90 or something a RY.

    but the biax cloth +-0/90 with a csm backing: 3.30 for 50 inch widths
    (pls forgive not being metric-even though Canada is metric- we still use the imperial system for Boat building).

    what I wondered and wanted to ask you was-
    1. would there be any difference in strength going with biax instead of WR cloth?
    2. couldn't I laminate my outer layer in a day using waxed(promoted) resin? if I had cool temps, and a few people helping?? it means only 6 layers on one day -three csm mats and 3 24 oz. biax cloth? then the following day the hull is righted- the mold removed-cradle set up and then the inner laminate done?

    I know this seems like a lot...I have no idea...Hankinson says its not impossible to do the layup in one shot.

    "that it requires just squeegee-ing the excess resin into the dry areas" ...keep it moving so it does not set up? what if I'm highly organized?

    3. ok maybe your correct on this- but lets suppose I tried to do the hand layup and got say two layers and part of a third done before the resin kicked off- wouldn't it be a matter of just sanding it down and then continuing the layup?

    the problem here is not that I cant learn it- but that W. Seemann himself has said that its nearly impossible to do it on c-flex hulls. this is why Sintes designs does not use the infusion technique.

    Groper- how hard would it be to close off the bag on a c-flex mold? this is what Seemann told me would be the deal breaker on that process?...
    isn't there a mastic that could work for bag sealing that could work on c-flex hulls?

    I have to be honest - I like the labour savings...that's a huge benefit. I would love perfect panels but I also have read of a lot of blunders and practicing before doing this... But I also don't know what I'm getting into as far as how much practice is needed...that can get costly... and trust me I am on a deadline. it seems prudent to stay in the realm of amateur means...even if its more open to knowing guarantees I will try this but you never know...

    btw- whats IIRC? sorry not familiar with that...;)
  7. tugboat

    tugboat Previous Member

    just to change the topic slightly- check out the engine I got for my tugboat-- a Petter-Mclaren with a parsow trans 1:1.

    its 20 hp at 1500 rpms- huge flywheel!. even at 1:1 it spun a 24 inch fan!
    It comes with a CP pitch prop mechanism too if I want it--it should be a sweet set-up///although it IS going to be replaced eventually with steam runs well.

    if it lasts me three more years I will be overjoyed!
    Ill likely keep the feathering setup for my steam plant.

    Attached Files:

  8. michael pierzga
    Joined: Dec 2008
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    michael pierzga Senior Member

    The ouside skin is easy to wet layup...the inside skin is not. On a 35 ft sailboat the inside skin wet layup took 5 guys, working flat out in space suites, all day to complete.

    Scantlings are best left to a NA.

    If you decide to go infusion PRACTICE...before you attack the hull.

    Many components in a boat..start with simple components as practice. Bulkheads, furniture..... Or even better build a very simple 8ft dingy. All the important lessons with be demonstrated during the dingy constrution and you will have a useful tender when finished.
  9. groper
    Joined: Jun 2011
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    groper Senior Member

    Yes, practice small first is a must with infusion...

    1. Biax or other stitched cloths are stronger than woven cloths of the same thickness because the fibres are held straight rather than concertina'd... You need fibres running in 3 general directions at least 0 +45 -45 degrees... Random strands doesn't hurt either as your just trying to build up a thickness with your layup. With thickness comes toughness which is what your after by the sounds of it.

    Promoted resin is not the same as waxed resin, completely different meaning... With polyester resin, you can get it with wax or without. If you get it without wax, the surface stays tacky just like a gel coat does. The following layers don't need any prep, they just go straight over the tacky previous one. When you want the final layer to go hard and tack free, you can add wax in styrene to the untaxed resin and will rise to the surface and allow the resin to cure tack free as it shields the resin from the oxygen in the atmosphere... It then behaves like a flow coat does. So flow coats have wax, gel coats have none.

    3. Moot point... If you use unwaxed laminating resin, you don't have to sand anything down before going over it after it kicks off... You need to plan how your going to do it, and choose the correct products to do it.

    You need to read through what I write carefully... I told you earlier, that after you apply the c flex , you complete the first full layer after that by wet laminating using an unwaxed resin. After that is cured with a tacky surface, you then proceed with your infusion layup as you then should have a sealed surface to seal your vac bag onto. It has to be sealed as any porosity will cause major problems with vacuum leaks and your infusion job. The first layer must be carefully done to get it all airtight.

    You don't need to do x layers on the outside and then x layers on the inside like is done wirh cored construction. You can do the whole lot just on the outside, over the c flex... Solid glass hulls act like a steel hull structure, you just need to build up a suitable thickness - like choosing the correct steel plate thickness. It will burn up heaps of resin and your labour, to build up this thickness you need- hence the infusion advice as it gets he whole lot done in 1 foul swoop.

    Building up a 5mm thickness solid glass hull via wet laminating by hand, is like trying to dig a swimming pool with a shovel and wheelbarrow... Infusing the same hull is like getting an excavator to dig the pool...
  10. Cat Cruiser
    Joined: Aug 2013
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    Cat Cruiser Junior Member

    A "male mould" --, A full size pattern / model to make a production mould off of is called a plug.
  11. tomas
    Joined: Nov 2012
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    tomas Senior Member

    I must have missed it. What deadline and why?
    What is your complete time frame for the whole project.

    As an inexperienced but aspiring builder-wannabe, I'm nervous for you reading this. Isn't this your dream project, that you've wrestled with for years and now you're making a crucial decision based on time? It seems like Groper's point about the labour savings is a major thing to consider carefully.

    Also, you're concerned about the expense of practising?
    Isn't that going to pay off in long-run?

    I want to see you achieve your dream so don't make a decision which you may regret because of what seems like a priority right now, only to find it wasn't so important later.
  12. rwatson
    Joined: Aug 2007
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    rwatson Senior Member

    You have to hurry up and use the fibreglass before it runs out :p

    Usually, its a case of spending the money before it gets used up on wasteful things like ... rent, food, electricity, medical bills ....:(
  13. tugboat

    tugboat Previous Member

    exactly! play the game not to lose, or play it to win"!

    ill let you ponder that one for a it relates to boat building...:p
  14. tugboat

    tugboat Previous Member

    Tomas- thanks - the dream is going to happen - its happening now -
    no worries my friend.

    the process cannot be done feasibly with resin infusion using c-flex. sadly it MUST be a hand layup- too many problems even with practice--pls read some of the last posts... I have talked to Will Seemann of Seemann composites where I got the c-flex from.

    He has tried it - in fact that's all his company does is resin infusion and he wont do it on c-flex- that tells me something....

    yes- there is a deadline for hull only no deck...personal reasons...

    but ten days of layup compared to a year of welding if done in steel?
    I think we can see the clear winner here...even if slower than vacuum bagging...but it will take more than 10 days-(what Groper said the layup would be if done by hand).

    I'd say that's a pretty fast boat build! I only need the Hull done by spring. after that it's as long as I want to take...

  15. SamSam
    Joined: Feb 2005
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    SamSam Senior Member

    Infusing on a male mold with a mix of vertical, horizontal and curved surfaces would be a different game than doing flat panels on a table, but not an impossibility. Another consideration of infusing would be pretty much eliminating the polyiso styrene fumes. I used the stuff so much I didn't mind it, but it does get into/saturate your body and does whatever it does. My wife said that when I was building a lot she could smell it on my breath when I was sleeping. I read an account of someone who kept a rabbitcage in the heated workshop and when they butchered the rabbits they were inedible because they tasted so strongly of styrene.

    But a mask and ventilation can take care of that and it's not like you will do it as a career.

    I don't remember the dimensions of your hull (8' X 25' ?) but I used to work in a 3 man shop making 12' x 30' ocean capable inboards. One guy did all the hull laminating (in a mold) and he turned out 1 hull a week. It was 2-3 barrels of resin and all the glass, but he did use his chop gun to shoot the catylised resin onto the laminate which he then rolled out. He never used the chopper gun on the hull. The hull was Gelcoat-set up-1 layer 1.5 oz mat - set up and then the next day he started laminating layers of 1.5 oz mat and 24 oz woven roven over and over until done. Some areas had more laminations. The keel area had upwards of an inch thickness and the upper sides 3/8 to 1/2 inch.
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