help with verticle laminations / foam core

Discussion in 'Fiberglass and Composite Boat Building' started by pescaloco, Oct 6, 2007.

  1. pescaloco
    Joined: Feb 2006
    Posts: 301
    Likes: 10, Points: 18, Legacy Rep: 81
    Location: so. california

    pescaloco Senior Member

    hello all,

    sure could use some advise, here is my delima.
    this is a home project being worked on solo.
    male mold frame and batton 3/4 divinicell and core cell foam, polyester resin
    1.5 oz mat 18 oz cloth. I am builing a pilot house for a 27 foot sportfisher.

    so any way there is a lot of large verticle panels to glass, I have made a slurry as suggest to prime the panels and have added some cabisol or micro ballons to the resin when doing the wet out. My problem is the thickened resing is hard to handle and I am having trouble getting the matt thourghly wetted out before it gels. EVEN when I do get a good section layed down there is more of the small white patches (air) scattered through the laminate
    than I care for ((and an concerned abount weak bonds)) and this is after dabbing with a stiff paint brush and using a roller.

    I do have some laminating experience and considered my self pretty good before this, but it has always been on a flat surface.

    so any insight or suggestions would be very much appreciated.

    thanks, Mark
     
  2. mongo75
    Joined: Aug 2007
    Posts: 262
    Likes: 6, Points: 0, Legacy Rep: 95
    Location: Orange County California

    mongo75 Senior Member

    I've heard of people using staples to hold the glass up while it sets so it won't slide off. That way you don't have to thicken your resin.
     
  3. Moosemiester
    Joined: Oct 2007
    Posts: 21
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Ohio, USA

    Moosemiester Junior Member

    Mark
    You didn't mention the brand of resin you are using -- Some are thicker than others, I find West System useless for heavy cloth on vertical surfaces (too thin); Universal Composites 635 3:1 much better. I'd try two layers of 10oz rather than one layer of 18.
     
  4. SamSam
    Joined: Feb 2005
    Posts: 3,900
    Likes: 198, Points: 63, Legacy Rep: 971
    Location: Coastal Georgia

    SamSam Senior Member

    Cabosil is a resin viscosity thickener (thixotropic), micro balloons are just a filler. Just use cabosil and not a whole lot of it. Your mix is too hot or you are trying to do too much at once or the air temp is too hot or you are working in the sun. You have too work fast with polyester, 20 minutes or so until gel starts. Use 9" paint rollers to apply resin and metal bubble busters to roll out the laminate. Have everything set out and set up before mixing in the hardener, tape or staple the glass in place if you have to, or roll the cabin on its side.
     
  5. Moosemiester
    Joined: Oct 2007
    Posts: 21
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Ohio, USA

    Moosemiester Junior Member

    Brush or Roller

    I agree that Cabosil is the way to go, takes more effort to sand but much stickier. It takes a lot of practice with any filler to get the consistency exactly right for the job at hand.

    Everyone has different experience, but I have had much better luck using 4" disposable brushes than rollers with heavier cloth. They are not too expensive if you buy them by the dozen from an internet source, rather than one at a time at your local hardware store.
     
  6. pescaloco
    Joined: Feb 2006
    Posts: 301
    Likes: 10, Points: 18, Legacy Rep: 81
    Location: so. california

    pescaloco Senior Member

    reply

    guys thanks for the replies. there were no replies for a while so I had not checed back recently.

    yes it is polyester, would have to go check the drum for the model #

    my big problems are the cabosil is very hard to mix into the resin to make the resin high viscosity yet completely fluid, the cabosil unlike the micro ballons seems to stick together in very small clumps, instead of a fine powder that easily mixes in, no matter how much mixing I do. which does not wet out good, which then leads to me taking too long for a given layup.

    the filler also causes the resing too loose it's opacity which leave me not knowing where the small entraped air bubbles are.

    how will the small scattered air (white spots) in the matt lay up efect the overall perfromance of the lamination ??

    thanks, mark
     
  7. SamSam
    Joined: Feb 2005
    Posts: 3,900
    Likes: 198, Points: 63, Legacy Rep: 971
    Location: Coastal Georgia

    SamSam Senior Member

    Try mixing a small quantity of resin with the whole amount of Cabosil needed, to make a paste or sludge and then slowly adding the rest of the resin, like mixing tomato soup from a can.
    The blurb below I got from this book...
    https://www.boatdesigns.com/prodinfo.asp?number=12-435
    I bold marked the by weight part. It means you accurately weigh your resin and then add 1-3% cabosil. Thixotropic is different than viscosity. Viscosity means something is thick or thin all the time..
    Whereas thixotropic is easily worked but then "thickens" once left alone.
    It could be you're putting so much Cabosil in it overides its thixotropic qualities and just becomes thick and viscous.
     
  8. pescaloco
    Joined: Feb 2006
    Posts: 301
    Likes: 10, Points: 18, Legacy Rep: 81
    Location: so. california

    pescaloco Senior Member

    thixotropic

    thanks, sam I kinda new that but have been equating the thickness (viscosity) of the resin with it's thixotropic qualities. the fillers are so light and airy it would seem to hard to measure weight when using a quantity of say 64 oz. of resin. what type of consistencey would I be looking for to get the resin to still be easily workable yet "thixotropic" ??

    is a resin rich lay up more likely to reduce or increase those small white air patches, no matter how much I roll out with a small diameter metal bubble buster I can't seem to get rid of them, my flat lay up's look good but I would like to improve the verticle ones.

    thanks, mark
     
  9. Moosemiester
    Joined: Oct 2007
    Posts: 21
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Ohio, USA

    Moosemiester Junior Member

    Measuring Filler

    I really like the West System books definition of different mixes:

    Ketchup
    Mayonnaise
    Peanut Butter

    I mix in cabosil to the consistency of ketchup when doing layup, which I'd wager puts it in that 1-3% ratio by weight -- as that is what the West books tell you to do.

    What a great forum!
     
  10. SamSam
    Joined: Feb 2005
    Posts: 3,900
    Likes: 198, Points: 63, Legacy Rep: 971
    Location: Coastal Georgia

    SamSam Senior Member

    When you say 64 oz., you are talking weight and not volume? 4 pounds as opposed to 2 quarts or 1/2 gallon? You can get "letter scales" at stationary stores like "Staples". They are cheap and measure small amounts. You can load the Cabosil in a baggie to weigh it, just be sure to subtract the weigh of the baggie. 1% of 64 oz. would be .64 oz, almost 3/4 oz. Try a 1% mix and see what happens.
    Have you tried laminating with straight resin? You might not need to do anything with the resin, which would make things simple. I've never had problems with vertical surfaces. Try a small test to see if it works, like a foot square using the same materials as the main project.

    Do the small white patches move around when you use the bubble buster? I guess what I'm saying is water drops will make white patches in a layup. Too little resin will make air pockets that are impossible to remove, the correct amount or resin rich will cure that problem. The resin being too thick to let air up through the weave could have been the problem, if that happens you have to chase them to an edge and let them out there.

    The way I would lay up what you're doing would be to slather on a good coat of resin on the foam, with a 9" medium nap paint roller, stick the mat on, slather on more resin and then quickly bubble bust that. If there is enough resin on the mat, stick the 18 oz "cloth" (woven roven?) on and quickly roll it down with a fairly dry roller to press it onto the mat, then put more resin on and bubble bust again. You want a fairly good amount of extra resin on the mat so it starts wetting out the cloth from the back, doing all the wet out from the front can trap air and be a nuisance to remove. If you have trapped air in big pockets or can chase them into one area, you can then stick something pointy into it and wiggle it around to open a hole in the weave to let the air escape. The bubble buster will close the weave back up.
     
  11. pescaloco
    Joined: Feb 2006
    Posts: 301
    Likes: 10, Points: 18, Legacy Rep: 81
    Location: so. california

    pescaloco Senior Member

    reply

    thanks moose and sam ......catsup would seem to be the consistency

    sam you of course said weight , i responed with the volume used 64oz or 1/2
    gallon) good suggestion on the letter scale. Even when i have a very resin rich layer of matt and can use the bubble roller to push a good sized pocket of liquid resin out to the edge i can see these smallish white spots. Im not sure it does't go back to an incomplete mix of the cabosil, the resin is fairly lumpy and then gets stringy from the matt fibers, and that has been making things harder. (definetly no water or othe contamination)

    the temperatures most times when I have a chance to work on this have been 80 degress and up, I have been trying to work 3ftx5ft sections at a time
    I would love to put the cloth straight down on the wet mat, I seem to have some trouble getting a thourough wet out on the cloth unless I heavily saturate the backside (substrate suface) and I guess it goes to some degree that I am not a quick as I could be and seem to fuss around too much trying to get every little spot air free.

    I just really want to do a good job, and don't want 100's & 100's of hour to not be have long term sucess.

    thanks, guys for you imput and advise

    mark
     
  12. the1much
    Joined: Jul 2007
    Posts: 3,897
    Likes: 44, Points: 0, Legacy Rep: 696
    Location: maine

    the1much hippie dreams

    do you use one of those metal rollers to take out the air? a brush isnt good to use with thickened resin, it just makes more air, but if you use a roller, try dipping it in resin first (just enough to get it wet,, not dripping off wet) then roll out the air
     
  13. pescaloco
    Joined: Feb 2006
    Posts: 301
    Likes: 10, Points: 18, Legacy Rep: 81
    Location: so. california

    pescaloco Senior Member

    rollers

    Much

    thanks for the great tip, that sounds like it could help.

    I'm not sure what is going on thought even when the matt seems to be very resin rich, I will see random patches of small aprox 1 milimeter white spots that may or may not roll out. it would seem that if the resin has not jelled and the matt is wet enough they should be able to worked out, the foam surface has been primed with resin and cabisol then squeegeed smooth and dried , so the suface is fair. Got any roller (buble buster) technique tips ??? like start in the middle / light pressure / heavy pressure.

    thanks, mark
     
  14. the1much
    Joined: Jul 2007
    Posts: 3,897
    Likes: 44, Points: 0, Legacy Rep: 696
    Location: maine

    the1much hippie dreams

    use as light pressure as needed to push it to the "closest" or toward the easiest way ( like try not rolling from a flat section around a radius),,,,but try rolling with heavy pressure in a spot where you think your "bubbles" will be,,like ive said before,,,i dont use alot of epoxy,,,,but try ya technique out on a small piece first. the one thing to remember tho is not so much pressure as to move your fabric around. and i have a acetone bucket at my side,, after a half minute or so of rolling,,, i dip the roller in acetone to clean,, if you dont, it starts "sticking" and that jus causes more typing lol ;)
    if i havent explained good nuff or missed anything jus let me know,,,heh,,im kinda simple ;)

    and your welcome mark

    Jim
     

  15. Landlubber
    Joined: Jun 2007
    Posts: 2,640
    Likes: 124, Points: 0, Legacy Rep: 1802
    Location: Brisbane

    Landlubber Senior Member

    Epoxy thinner of course when working with epoxy for cleaning the rollers.

    Acetone for working with polyester resin for cleaning the rollers.

    Otherwise good advice.
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.