ahoy matey .. first fiberglass plug and i have a concern

Discussion in 'Fiberglass and Composite Boat Building' started by lake pirate rrr, Aug 8, 2016.

  1. lake pirate rrr
    Joined: Aug 2016
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    lake pirate rrr Junior Member

    rrr ..

    so i have made some progress .. and some mistakes ..

    but all is steaming foreward .. just tacking off to get there rrr..

    i tried laying that finish puddy over top of resin .. but the heat caused near instantaneous hardening .. and i had to quickly scrape off what i had layed and abandoned that idea ..

    though i shouldn't have as i soon found out .. i should have smoothed out the whole backside in filler .. as i did with the next two plugs .. but the first .. i got cocky rrr.. and just layed up a matte over the plug and went to bustin' bubbles ..

    well .. maybe it was just because it was my first time idk .. but i got 100 daggon bubbles trapped in there !:rolleyes:

    so .. i drilled them out and filled with resin and a big ol' syringe ..

    and i finally came to the conclusion .. this layering matte up for a plug is for the birds ..

    i evened out the other plugs with bondo and sealed them with resin ..

    i went to town and grabbed 2 gallons of advantage 801 'bondo'

    i'm gonna mix up about a whole grocery bag of csm fragments and a good bit of resin into the bondo to make 'rondoglass'

    resin - fiberglass - bondo

    and pour the mixture -- in medium small batches - exotherm - into steel frames .. that should save me a toonnne of money in resin .. and a tonne of time .. and with my lackluster skills at laminating .. solid chunks of reinforced plastic is sure to be stronger then layer upon layer of glass ..

    i think it's gonna work out great .. i'm gonna finish the moulds tomorow with the rondoglass frame and pour out .. wait a day .. pull the plugs .. and plan on producing the first parts this upcomming week ..

  2. lake pirate rrr
    Joined: Aug 2016
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    Location: nashville

    lake pirate rrr Junior Member

    ahoy matey ..

    i bring great news from my journeys afar ..

    i pulled the plug from my first mold successfully !!

    so a few observations ... the exotherm heat of the rondoglass did exceed the working temp of the wax and formed a nice tite bond between the plug and mold surface ..

    fortunatly .. when i built the plug .. i had in mind that it might be necessary to destroy it in order to facilitate removal .. so i only spotted in .. not fully welded seams .. i glued some joints and used automotive grade steel instead of a solid plug .. so although the plug was throughly destroyed in removal ..

    the mold looks excelente !

    not perfect mind you .. . there was an occurance of reaction between the mekp tool gel and the urethane paint .. it blistered into tiny pimples all across the surface .. though .. that's not a big deal .. overall the shape is excelent ..

    i will be laying down sanding gelcoat first .. or 2k build primer .. and finish sanding the final parts anyway ..

    the only gator .. is a large one .. but on the flange surface .. where i didn't really care if that happened so paid less attention to that part .. as it is not actually part of the mold surface ..

    most definitely a success by my standards ..

    no mirror finish .. but i had always intended to do some finishing on the final part .. the goal was .. 'not alot of finishing' because i do want to make good use of my time ..

    overall the thickness of the rondoglass measures on average an inch and a half .. variably 1 and a quarter to two inches ..

    it's a 'plastic brick' and weights out to 11lbs ..

    after some time i hit on just forming a dam of foam floor underlayment around the plug .. and pouring in to there .. i will finish trimming the sharp corners and bondo it smoothe ..

    then hammer the entire surface with a few light coats of resin ..

    .. . without firther adue

    (the lighting looks pink -- but it be a nice orange)

    Attached Files:

  3. SamSam
    Joined: Feb 2005
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    Location: Coastal Georgia

    SamSam Senior Member

    It came apart so there's that, but it looks pretty rough. The same time spent on making the plug acceptable looking (and thereby the mold) will now have to be spent on every piece to make them acceptable looking. But, it will be a difficult piece to layup, with the narrow cavity and various corners and all, so no matter how well the mold surface was finished, there will probably be touch up work to do anyway. So, if it works for you, it's all good.

    There doesn't look to be much draft to the mold, you'll have to be wary of the pimples and stuff locking the part in the mold and making it irremovable, since you can't destroy the part like you did the plug to get it out of the mold.

    What is the part going to be?
  4. lake pirate rrr
    Joined: Aug 2016
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    lake pirate rrr Junior Member

    i too share your concerns .. during this process i have had to lower my expectation to .. not screwing up bad enough that any mistake is non recoverable .. and in that .. thus far i have acheived this modest goal ..

    i share your exact concerns .. and the mold is not perfect .. though for my first time .. i was expecting some mistakes .. but none so bad that the project would be lost ..

    about the corners ... especially the top and bottom rectangular bits .. these were only for casting and as markers for cutting .. as here these pieces are cut out to make room for inner structure .. there would be no way to laminate that without air bubbles .. but that's okay as i will be cutting there .. also these places i think since they will be cut out .. i can be rough with here and this areas will be my primary removal points ..

    yes though it will be a difficult layup anyway .. no way around it .. not an ideal piece to begin learning i must admit .. though i think i can work with this ..

    there are a great number of 'pimples' but they are very small indeed .. so much that i think i can sand the majority of the imperfections out .. as well as gently give the plug another degree or two of taper .. i will stop if i get thin in the tooling .. i'm very good at sanding .. so i don't think this will be a problem .. though it will be difficult to get in there ..

    these molds only have to work for pulling a good 20 pieces .. for sure .. i will rework a greater draft on one of each .. as well as finish out the imperfections .. and apply duratech surfacing primer .. and remake the molds .. weather these molds are working well or not .. i do want to make better ones .. and can never hurt to have extras .. i intend to improve my techniques as i make each piece and learn as i go .. after a few dozen finished parts i should have some idea on how to improve the molds and make new flanges on a nice finished part .. and go another round ..

    yes .. i cannot destroy the parts like the plug .. but i think i can go to the carwash and blast out the parts if i need to .. until the mold is sufficiently surfaced and what do you call .. aged .. or worked out so that the parts are smoothly removable ..

    also .. while looking up some info on good semi permenant mold release .. i found a company .. mclube .. i'm not advertising for them .. and haven't tried it yet .. but their release agent seems well liked and they offer to send out a sample .. so i went to their website and requested thus sample .. hopefully it is much more easy releasing than wax and this could help with the difficult shape and contours ..

    this is one piece of an updated grille design for older ford f-series pickup trucks .. specificly 80-86 bullnose style .. i am also a ford diesel enthusiast .. and have a liking for the older .. all mechanical .. idi engines .. . i have the 6.9 idi in my 4x4 truck .. i like it very much and it gets great mpg .. and power ..

    in the far away future i would like to build a large cold molded wooden vessel with 2 inboard idi engines .. 60' plus motor sailer would be ideal ..

    i think the idi engine would be a great motor for such a boat .. though i'm not sure .. i live in tennessee .. and eastern cedars here are 'trash trees' ..

    i am desiring to also build a diesel driven band saw and ask any local tree companies for what they have to give .. .. so that i can cut 1/4 in veneers .. of the hearts of any cedars .. it would take several years to pile up enough 1/4 heartwood veneers to make a 2 1/2 inch - 3 inch thick hull ..

    at this point it's just an idea .. i don't know if i can ever do it .. but i certainly can't afford to buy a yacht .. so perhaps .. if i build the mill .. i will stockpile all the cedar strips i can cut and dream . .. i need a real boat to upgrade from lake pirate to bluewater pirate .. rrr
  5. lake pirate rrr
    Joined: Aug 2016
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    Location: nashville

    lake pirate rrr Junior Member

    ahoy matey ..

    i've pulled all three molds now ..

    and i'm really pleased with this rondoglass backing .. i slathered resin over top of it and they're now water proof bricks ..

    i went over them with my standard sanding regiment .. razor .. 320 .. 400 .. 500.. 600 ..800 .. 1200 .. 1500 .. 2000 ..3000 .. compound .. machine polish ..

    and they really came out nice .. i've added a delicate taper .. with as much room as i felt the tooling would allow .. and sanded smooth 85% of the pimpling .. the molds are a nice high gloss ..

    though there are slight high and low spots and some 'effects' perhaps of the csm or perhaps localized pre release .. i'm not really sure .. i have seen this in fiberglass before .. it's not as straight as the plugs were in metal ..

    though i'm still pleased overall .. i've cleaned the flanges and am about to tape them off and wax the molds ..

    ohh also i allowed the molds to cure in the sunlight and with a heat gun ..

    so gonna wax em.. tape em.. and just to be sure .. i'm gonna just pour pva directly into the cavities and slosh them around covering every surface .. and drain it back out .. just for the first few pulls.

    overall .. looking objectively i would rate ..

    the plugs that went in at 9.5

    the molds that came out at 8.5

    and i may loose another point during layup ..

    though i can make a 7.5 a 9.5 again in 10 minutes of sanding for each piece ..

    so all in all i'm pleased .. i'm sure i will improve with my next ones ..

    i must say though i do like the rondoglass .. on my second piece like the first .. i just pressed in the sides .. got 3 stir sticks and some vice grips .. grabed the plug .. put the stir sticks on the flange to act as a lever .. and pulled the other 2 plugs right out ..

    that rondoglass is tough enough to act against as a lever so part removal shouldn't be any problem going forward ..
  6. lake pirate rrr
    Joined: Aug 2016
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    Location: nashville

    lake pirate rrr Junior Member

    ah harr

    I'm back from a voyage. .. questing fer rum and whenches rrr

    everything is going very well now .. i'm using semi permanent mold release and the molds be pullin' tough n' clean .. beginning to gather materials and tools for vacuum infusion. .. to increase speed . . Consitancy .. cleanlines .. in serial production ..

    here be me website >>


    i'm not pushing me products on this here boat site rrr .. just sharing for those who'd followed this thread and rrr interested //
  7. redreuben
    Joined: Jan 2009
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    Location: South Lake Western Australia

    redreuben redreuben

    Pirates from Nashville now I've seen everything. What happened did they run out of Bourbon ?
    Aaaarrrrrrr :)

  8. lake pirate rrr
    Joined: Aug 2016
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    Location: nashville

    lake pirate rrr Junior Member

    tis a shame .. we rrr nearly landlocked. ..

    but plunder be our duty as long as there be booty ..

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