q cell powders and fairing compound

Discussion in 'Fiberglass and Composite Boat Building' started by JINLEE, May 9, 2014.

  1. JINLEE
    Joined: Nov 2011
    Posts: 17
    Likes: 0, Points: 1, Legacy Rep: 10
    Location: KOREA

    JINLEE Junior Member

    Hi

    Has anyone used qcell powders mixed with 2pack epoxy resin for fairing purpose?

    I think they are much sandable but am not sure if there strong and competitive than using compounds sold in set such as awlfair and stuff.

    I would also like to know well known makers or suppliers of the qcell powders that are suitable for marine use.

    Thanks.
     
  2. waikikin
    Joined: Jan 2006
    Posts: 2,383
    Likes: 151, Points: 73, Legacy Rep: 871
    Location: Australia

    waikikin Senior Member

    JINLEE,

    Qcells are commonly used, add a little colloidal silica also & the mix tools off without "dragging" off the tool/broadknife edge.

    Jeff
     
  3. JINLEE
    Joined: Nov 2011
    Posts: 17
    Likes: 0, Points: 1, Legacy Rep: 10
    Location: KOREA

    JINLEE Junior Member

    Hi Jeff, thanks for your advise. Do you have any idea of mixing ratio for q cell and silica powders? Do you also know where I can purchase them in volume? something like M/T basis. thanks again.
     
  4. waikikin
    Joined: Jan 2006
    Posts: 2,383
    Likes: 151, Points: 73, Legacy Rep: 871
    Location: Australia

    waikikin Senior Member

    JINLEE,
    I get my Qcells from FGI or Fiberglass Australasia, I don't know what mt is except for empty as in "the tank is empty"
    Ratio is developed for your purpose, on decks a runnier "flow bog" can be good, for vertical needs a thicker mix.

    Regards from Jeff
     
  5. JINLEE
    Joined: Nov 2011
    Posts: 17
    Likes: 0, Points: 1, Legacy Rep: 10
    Location: KOREA

    JINLEE Junior Member

    Hi Jeff,

    Thanks again for your advise. FYI, M/T means metric tons.
    Thanks Jeff.
     
  6. Westfield 11
    Joined: Apr 2008
    Posts: 215
    Likes: 8, Points: 0, Legacy Rep: 95
    Location: Los Angeles

    Westfield 11 Senior Member

    Jeff, I am always worried that a runnier mix will be harded to sand compared to a drier one more suited to vertical surfaces. Is there much difference? The same with the silica: does it affect sandability?
     
  7. waikikin
    Joined: Jan 2006
    Posts: 2,383
    Likes: 151, Points: 73, Legacy Rep: 871
    Location: Australia

    waikikin Senior Member

    Yes, silica affects sandability- for fairing compound use the minimum for ease of application. For decks a slightly runnier mix is fine..... but not too runny! There's a "theory" that the the ballon fillers floa tat the surface giving a easy sand crust................. never looked through a microscope to suss the cross section though, west 410 makes a great deck flow bog & definatly seems to do this. Also be aware that a dry surface will "scavenge" resin from the filler mix, this can lead to it becoming unworkable on the surface if too dry a mix. The critical aspect to sandability is actually neat/accurate application to the surface to be faired, this leads to less sanding;).... whoever applies the fill should also sand the fill, this leads to learning!

    Jeff.
     
  8. Steve W
    Joined: Jul 2004
    Posts: 1,824
    Likes: 63, Points: 48, Legacy Rep: 608
    Location: Duluth, Minnesota

    Steve W Senior Member

    I typically use a 50:50 blend of Q cell and silica, it sands just fine for me and spreads nicely, what I find is that without a decent amount of silica it is just too runny for my purposes. Another thing I find is that often the silica is lumpy, so I use an old blender to make my blend, a cup of silica, a cup of Q cell, put the lid on and blend, I make up enough for the days work and store it in a 5 gal bucket with an airtight lid.

    Steve.
     
  9. jorgepease
    Joined: Feb 2012
    Posts: 1,620
    Likes: 49, Points: 48, Legacy Rep: 75
    Location: Florida

    jorgepease Senior Member

    I agree on mixing the fillers first, I mix 4 gallons of micro balloons to 1 gallon of silica for most of my project and then adjust resin for consistency.

    I find the silica gives less slump and helps to sand easier if you don't over due it. Keeps the paper from getting clogged.

    Also what was mentioned above about the surface drying out the mix is super true, make sure you have that completely cleaned off between sandings.

    Powermix your fillers with the epoxy to get the best mix
     
  10. redreuben
    Joined: Jan 2009
    Posts: 1,829
    Likes: 149, Points: 63, Legacy Rep: 349
    Location: South Lake Western Australia

    redreuben redreuben

    I think the blend we used when I was working for a builder was 5 balloons to 3 silica.
     
  11. JINLEE
    Joined: Nov 2011
    Posts: 17
    Likes: 0, Points: 1, Legacy Rep: 10
    Location: KOREA

    JINLEE Junior Member

    Thanks guys all.

    Very helpful comments. Thanks guys.
     
  12. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 488, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Wow, 50/50 q-cells to silica. I use silica as a viscosity control agent only and just enough to stiff a mixture. Typically a 3:1 or 4:1 mix ratio is common, again using just enough silica to get the viscosity desired.

    Now this isn't the case with structural applications, like bonding and fillets, but is the situation with all cosmetic applications.
     
  13. groper
    Joined: Jun 2011
    Posts: 2,467
    Likes: 123, Points: 73, Legacy Rep: 693
    Location: australia

    groper Senior Member

    Yeah I'll say... My mix for fairing and sanding is more like 8:1... More qcell and less silica gives lower total density - easy to sand. More silica gives higher density, harder to sand...
     

  14. Steve W
    Joined: Jul 2004
    Posts: 1,824
    Likes: 63, Points: 48, Legacy Rep: 608
    Location: Duluth, Minnesota

    Steve W Senior Member

    I have no problem sanding at all with a 50:50 blend, but then i don't use sandpaper when fairing a job of any size, i can understand how it would seem hard to sand with sandpaper. I will only use fartrock,( foam glass) for fairing, I have no patience for sandpaper.

    Steve.
     
Loading...
Similar Threads
  1. Gasdok
    Replies:
    4
    Views:
    463
  2. eam
    Replies:
    3
    Views:
    1,300
  3. Jolly Mon
    Replies:
    15
    Views:
    2,335
  4. guzzis3
    Replies:
    26
    Views:
    4,385
  5. fallguy
    Replies:
    19
    Views:
    1,955
  6. mrybas
    Replies:
    6
    Views:
    2,117
  7. catsketcher
    Replies:
    9
    Views:
    1,650
  8. fallguy
    Replies:
    130
    Views:
    11,066
  9. fly186
    Replies:
    10
    Views:
    1,672
  10. fly186
    Replies:
    11
    Views:
    2,676
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.