I need help to learn how to make perfect vernish on our veneered honeycomb panels

Discussion in 'Materials' started by teakcell, Jan 16, 2009.

  1. robherc
    Joined: Dec 2008
    Posts: 432
    Likes: 5, Points: 0, Legacy Rep: 102
    Location: US/TX

    robherc Designer/Hobbyist

    The "el-cheapo" foam brushes I was referring to were not a specific brand name. I was using "el-cheapo" to refer to any cheap foam brush that you can pick up at a discount store. The ones I use cost me about $3 for a package of 10 brushes.
    As far as technique goes, I dip just the tip of the angled part of the foam 1-2mm into the varnish (I like spar urethane...good all-weather varnish, but it's not especially cheap) then smooth it onto the surface. Each dip covers about 7-15cm of surface, the same width as the brush, depending on how much urethane soaked into the foam. It's a VERY labor-intensive process, but it yields a good, high-gloss finish coat for me.

    A HVLP (High-Volume Low-Pressure) sprays more media (varnish) with less air pressure than a "conventional" air spray gun. I'd still highly recommend an airless spray gun for varnish though, as most HVLP and "standard-pressure" air spray-guns require you to thin your paint/varnish, and this won't help smooth your finish coat much...although it WILL make the process require more coats to get to the same build thickness.
     
  2. apex1

    apex1 Guest

    As usual I widely agree with your recommendations, but here is a possible solution to control viscosity by adding a diluent based on epoxypropoxy.
    That does not weaken the crosssections too much because it is a ACTIVE diluent. For cabinetry it should be fine anyway, I would not recommend in applications with highly induced stress.
    http://www.ezentrumbilder.de/rg/pdf/si_en_Active_diluent_EPD_BD.pdf
    and:
    http://shop.ezentrum.de/4DCGI/ezshop?hid=27&sprachnr=2

    best regards
    Richard
     
  3. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 491, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Richard, I didn't see anything on that site that was a diluent. Can you provide a direct link to the specific product?

    Teakcell, most of the chemicals typically used to thin epoxy, will alter the physical properties of the cured epoxy. Most affect the molecular crosslinking that takes place, by working against a complete 3 dimensional link or physically presenting certain percentages of 2 dimensional linkage from occurring. In all cases, this lose of linkage will weaken the epoxy. In defense of this "thinned" epoxy debate, there are times when you may want to change the physical properties of the cured matrix and specific chemical dilution can provide a means toward this. Preforming this with predictable results can be a tedious and drawn out process of testing and re-testing. I personally have a few different mixtures that I use regularly, in application specific roles. They've been repeatedly tested and now have stood the test of a couple of decades in service, so I can predict their performance accurately. None of my special mixtures are used in any finishing applications.
     
  4. teakcell
    Joined: Jan 2009
    Posts: 54
    Likes: 2, Points: 0, Legacy Rep: 17
    Location: myanmar

    teakcell Junior Member

    Can you be more specific with the mixture that you use? You said that ep can be liquid when heat. Which temperature do you advise and which tools do you recommend to apply the ep and pu ?
     
  5. teakcell
    Joined: Jan 2009
    Posts: 54
    Likes: 2, Points: 0, Legacy Rep: 17
    Location: myanmar

    teakcell Junior Member

    Would anyone knows where to find plans or drawing, explanations on how to make a proper painting room? Which air temperature do wee need, air flow in and out ...
     
  6. robherc
    Joined: Dec 2008
    Posts: 432
    Likes: 5, Points: 0, Legacy Rep: 102
    Location: US/TX

    robherc Designer/Hobbyist

    Hmmm, just a thought...

    Why not simply use a lower-viscosity epoxy? Depending on the finished properties you're looking for, there are some excellent epoxies out there with viscosities that go down to below 500cps...some are even thinner than most varnish. surely any of those would work very well for a surface-coat epoxy to fully saturate your veneer prior to varnishing. Some of them (heat-cured) even have pretty favorable hardness, strength, and heat-deflection properties, good enough for usage in (some) structural laminates.
     
  7. teakcell
    Joined: Jan 2009
    Posts: 54
    Likes: 2, Points: 0, Legacy Rep: 17
    Location: myanmar

    teakcell Junior Member

    Good idea but I have troubles finding more than one supplier here! We have have one type of glue. I can always import and stock but I try to avoid that as I have enough stock.
     
  8. robherc
    Joined: Dec 2008
    Posts: 432
    Likes: 5, Points: 0, Legacy Rep: 102
    Location: US/TX

    robherc Designer/Hobbyist

    I'd recommend doing a patent search for "paint spray room" with Google at http://www.google.com/patents . Any patent that's over 7 years old is considered "expired" and can be used by anyone.
     
  9. apex1

    apex1 Guest

    PAR
    unfortunately not possible, but:
    http://www.r-g.de/
    change language..... left side bottom
    goto E-shop.........click......Epoxy resins....click.......EP additives ..aahhh
    see them all ... be jealous....... bloody Huns:D

    With pleasure
    Richard
     
  10. teakcell
    Joined: Jan 2009
    Posts: 54
    Likes: 2, Points: 0, Legacy Rep: 17
    Location: myanmar

    teakcell Junior Member

    well thought. Thank you
     
  11. apex1

    apex1 Guest

  12. Kaptin-Jer
    Joined: Mar 2004
    Posts: 570
    Likes: 18, Points: 0, Legacy Rep: 206
    Location: South Florida

    Kaptin-Jer Semi-Pro

    I don't know the availability where you are, but I have been using paperbacked veneer and I have not had any bleed through. I am not vacuum bagging only rolling with a laminate roller, low tech but it has been working well.
     
  13. apex1

    apex1 Guest

    Kaptain
    He is in Burma, almost nothing available there. And his problem might be that he uses Teak (oily), but he must use Teak.

    Regards
    Richard
     
  14. teakcell
    Joined: Jan 2009
    Posts: 54
    Likes: 2, Points: 0, Legacy Rep: 17
    Location: myanmar

    teakcell Junior Member

    Yes, good idea too. I don't really have trouble with Ep going through the veneer and I would even say that I like that because it cannot be better bonded. My problem comes after applying another layer of ep and additionnal Pu varnish in order to reach a top mirror quality varnish. I have only one kind of epoxy available in the local market. I can always import but it is a real trouble here. So, as long as I can do with available products, I will try.
     

  15. teakcell
    Joined: Jan 2009
    Posts: 54
    Likes: 2, Points: 0, Legacy Rep: 17
    Location: myanmar

    teakcell Junior Member

    I did. Thanks
     
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.