Finish Help?

Discussion in 'General Slingshot Discussions' started by Withak, Sep 24, 2013.

  1. Withak

    Withak aka Whitehawk!

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    I think I may have messed up by being a little to anxious when I should have been patient.

    I'm working on a little pocket sling using an interesting method (which I'll show when it's done). I was finishing the wood with BLO, about 5 coats. This was to be followed with spray poly. Problem is, I'm on now my 3rd coat of spray poly and for some reason, the poly won't dry completely. I've used this poly numerous times before but I've not run into this problem, so I thought I'd throw the question out to the community.

    My first thought is that I didn't wait long enough for the BLO to really 'dry' before I started coating with the poly. It had been several hours since the last coat and the sling felt dry in my hand. Perhaps I didn't wait long enough? Also, it's been raining pretty heavily here the last 48 hours, which means really high humidity and lower temps.

    At this point it's too tacky to sand, it would just gum up the sandpaper. I decided to give it a third coat remembering that someone had said that poly can be a little 'blotchy' over oil finishes. But to have it remain tacky, after a full 24 hours of dry time??

    So, experts in the field of catapultary and slingonometry, what say you? Did I "BLO" it?? And not wait long enough? Any suggestions on how I can fix this? Should I just keep applying more poly and hope the problem goes away? Let it sit another day or two? What would you do?
     
  2. flicks

    flicks ...lost in the woods....

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    I've used poly spray several times on BLO without any problems. How long did you wait until spraying the poly? BLO should dry at least 12 hrs. Usually when you use Poly on wet material, you will get "clouds" in the paint. I assume the can has been shaked well and the temerature was not below 18C degrees.
    The layers of poly have to be very thin. Wait until the surface is dry before applying the next one. You should not get a glossy surface before layer #5 is spayed.
    Anyhow, if your surface remains tacky after drying 24 hrs in a warm room, I would remove the paint with acetone and start the painting process again.
    Good luck
     

  3. G_Y

    G_Y aiming the less

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    When poly (with hardener) is not drying fast enough (because the % of hardener was not enough) it could help to put it in the baking oven with 70 degrees C = 158 degrees F for two hours. This is also good to harden GRP = GFK parts faster and better.
     
    Last edited: Sep 24, 2013
  4. dolomite

    dolomite Banned

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    What flicks said. I let my raw linseed dry for three days but with blo a day should do it. good luck.
     
  5. Withak

    Withak aka Whitehawk!

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    Thanks guys for some good suggestions.

    I definitely didn't give it enough time to dry, just got too anxious to move on! I'm sure that doesn't happen to you guys though, right? ;)

    I'll check it again when I get home tonight, that's almost 24-hour dry time on the last coat of poly. If it's still tacky, I may try putting it in a very low oven for just a bit and see if that helps. If not, I guess I may have to do what flicks suggests and strip off the poly and start again.

    I should have waited for that BLO to dry a bit longer :( I think I only gave it about 4 hours tops. To my credit, I've finished over BLO that quickly before, but this one has more BLO on it than previous slingshots. All part of the learning process.
     
  6. Arturo Borquez

    Arturo Borquez Administrator

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    A nice finish I've tried and I like because is not glossy and have a natural look is a mix of beeswax melted and diluted with turpentine it covers with a nice golden colour ...
    Cheers
    Arturo
     
  7. Withak

    Withak aka Whitehawk!

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    I've heard of that finish method, but haven't tried it yet. Tell me, does the finish stand up to use over time? Does it eventually have to be re-applied? What kind of ratio is the dilution of the beeswax to turpentine?
     
  8. Jeremy

    Jeremy Senior member who totally rocks a pink Scout! Pink

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    I am also interested in this information. :)
     
  9. BeMahoney

    BeMahoney Builder of things

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    double cooked linseed oil with chinese nut oil

    Hi everyone!

    The best coating i know is "le tonkinois":

    http://www.letonkinois.de/(S(g24gkj45qokvay45zn2llz55))/Default.aspx

    mixed with "Gelomat" it gives a matte shine.

    That stuff looking like toothpaste is like liquid glass,
    most awesome stuff I can thinkof for cracks an holes..

    Anyway, that stuff is outstanding!- turns wood into a transparent
    3D-material, just like a Hologram..

    And its hardening like lacquer!

    Be
     
  10. Arturo Borquez

    Arturo Borquez Administrator

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    the recipe I do is more or less variable maybe 50%/50% in volume, it must be enough "liquid" to allow the wood suck the mix. I use 2 layers, the first more diluted then when dries (quick, not much time) a strong leather polishing and the second layer more viscous (as some turpentine evaporates), dry and another leather polishing, I add a soft paper towel final polishing. Beware with the turpentine fumes and use 2 pots, the external pot filled with water and the inner pot to make the mixture, when beeswax melts add the turpentine slowly and stirring it until it gets homogeneous and take the pots out of fire, use a spoon to bath the wood over the inner pot holding with piece of cloth and a glove (as it is hot) to avoid burn your hand ...
    it will turn waterproof and lasts a long time ...
    Cheers
    Arturo
     
    Last edited: Sep 24, 2013
  11. Withak

    Withak aka Whitehawk!

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    Sounds interesting Be, I wonder if there is an equivalent product here in the states? I tried a couple of quick searches for Le Tonkinois and came up with nothing here.
     
  12. Withak

    Withak aka Whitehawk!

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    Thank you Arturo for sharing that information. It sounds like several folks here may benefit from your finishing 'recipe'.
     
  13. Arturo Borquez

    Arturo Borquez Administrator

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    It's not mine, Quercusuber in SSF shared, it is a 19 century recipe from fine Portuguese cabinetmakers ...
    Cheers
    Arturo
     
  14. Withak

    Withak aka Whitehawk!

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    Good news, I hope. I got home from work today and checked the finish. It was almost completely dry - at least dry enough I could do my first mid-way sanding of the poly finish. It took a full 24 hours for that last coat to dry, inside. Based on what others said, it was likely a combination of not giving the BLO sufficient time to dry along with rather high humidity and lower temps here in the last few days. So next coat is on tonight - which I'll give another 24 hours before coating again. Should be ready for reveal in a few days.
     
  15. Withak

    Withak aka Whitehawk!

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    Well then we'll thank you for sharing and those fine 19th century Portuguese cabinet makers for developing it!
     
  16. BeMahoney

    BeMahoney Builder of things

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  17. Withak

    Withak aka Whitehawk!

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    Yikes! That's expensive stuff, at least here in the states. I followed your link and it would cost me almost $50 USD for (1) 1L can!! I did another search for Oil/Varnish and found there are other products on the market here that provide the same or very similar mixes. I also found a site that shows you how to make it yourself with the individual components, and it's not difficult. Thanks for the suggestion. I'll be looking further into this as I work with new finishes.
     
  18. BeMahoney

    BeMahoney Builder of things

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    One litre

    that one litre would suffice for at least 40 Slingshots..

    Maybe I´ll better send you a little bottle..

    I´m busy right now, we´ll see later

    greetings,

    Be
     
  19. BeMahoney

    BeMahoney Builder of things

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    Caution! -risk of fire!

    Hey etrain,

    one thing that must be known about linseed is that it used to be
    No1 cause for burning carpenter's shops !!!!!

    It is self- igniting ! ! ! (Therefore there always was a bucket filled with water
    to put those rags into which were used to apply linseed oil!)

    That´s why I always put those rag outside (to be safe!)

    The other question is if it may beshipped just like that
    (or will this be a terrorist act? :) )


    Be
     
  20. dolomite

    dolomite Banned

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    Be, it should be fine with proper marking of contents.