InterCoat Base

SpinnerSpinner Posts: 235Member ✭✭✭
@onehitwonder Question...

Can OHW intercoat be applied directly to an aluminum surface as a base coat in the hydrographic process?

For the last year and a half, I have been using OHW paints on these aluminum parts with great success. I have dipped hundreds of the same parts using the same prep and finishing process without any adhesion failures.

A couple of weeks ago, I experimented using intercoat as a base directly on the aluminum. This has a cool looking effect with some patterns to have the aluminum show through. I have also tried a couple of the Candy intercoats hoping for the same effect. They look is even cooler!

However, while pulling off the masking, 3 hours or so after clearcoat (as usual) the clear, dip, and intercoat came right off with the masking vinyl and blue tape. Peeled like a banana!

The same pieces finished with OHW paint colors , prepped and finished right alongside with the intercoat pieces came out just fine with not one adhesion failure.

So, can intercoat be applied directly to the aluminum?

The day I applied the intercoat base was extra humid and hot. and the intercoat looked to have a "blush." My spray shop is not conditioned and so I am at the mercy of the ambient temperature and humidity. Back when the weather was cooler and less humid, the intercoat went on very clear... I could hardly tell it was there.

BTW, these particular parts were from an aerosol can as I was testing just a few samples.

My typical prep routine is to wash the parts with hot soapy water (Dawn). After they dry, I mask as needed, then wipe with Alchohol before spraying the base coat.

Thanks, and I hope this is just my process or weather conditions as the IC has a neat look under some patterns.



  • norcalfranknorcalfrank Posts: 1,055Member ✭✭✭
    Do you profile (abrade) the parts before base coating them? If not, that could be your problem. OHW recomends a minimum of 400 grit abrasion before their paint.
  • SpinnerSpinner Posts: 235Member ✭✭✭
    Yes, the parts are abraded with 80 grit on my.lathe.
    this is the actual part that I peeled clean.
  • SpinnerSpinner Posts: 235Member ✭✭✭
    Sometimes, I will refinish parts  (because of other issues) by soaking with acetone. That's how good the adhesion usually is.
  • norcalfranknorcalfrank Posts: 1,055Member ✭✭✭
    I have never had that problem with OHW intercoat clear.
  • onehitwonderonehitwonder Posts: 2,808Member, Business Ninja ✭✭✭✭✭
    edited June 2018
    Hi Chris, you may want to try a few extra coats of intercoat in the future- due to the nature of the activator and the hardness of the aluminum, there is a good chance that the thin layer of intercoat was compromised- can you try 3-4 coats, and do an adhesion test before you clear?
  • SpinnerSpinner Posts: 235Member ✭✭✭
    Thanks, Jason.
    Yes I will try that. How long after I base coat should I wait for the test?
    I am suspicious of the blushing I mentioned due to humidity? Could the IC, or paint for that matter, hold moisture within?
  • SpinnerSpinner Posts: 235Member ✭✭✭
    I will also test with a first coat of white and Metallic silver under the IC to see what happens.
  • SpinnerSpinner Posts: 235Member ✭✭✭
    Update. ..
    Been working wit jj in texts, but here is where we are..
    I prepped and repainted three parts using my usual procedure outlined above. After an hour or so i did an adhesion test with both packing and duct tape...

    So far so good. Left to right is IC Ruby, white, white with IC ruby.

    Next  I will dip these using the same film and activator combo that led to earlier failure . Then do another adhesion test and see what happens...
    Tank is heating up.

    BTW, I will warm up a part then hit it with the ruby IC to see if the blush will go away.
  • SpinnerSpinner Posts: 235Member ✭✭✭
    Warming the part then hitting it with the Ruby took the blush right out.
    Here are the Ruby and white parts dipped with the same activator and film as my failures from earlier. Need to let them set up then do another adhesion test...

  • DeviousDipsDeviousDips Posts: 1,877Member ✭✭✭✭✭
  • MidOhioHydrographicsMidOhioHydrographics Posts: 10,032Member, Moderator, Business Ninja El Moderator
    Looking good and a VERY technical and informative thread. Thank you for sharing!
  • onehitwonderonehitwonder Posts: 2,808Member, Business Ninja ✭✭✭✭✭
    Congrats - looks like we got to the bottom of it!
  • SpinnerSpinner Posts: 235Member ✭✭✭
    After the dip set up overnight , I did another adhesion te test. (That is such a hard thing to do on a good looking part!) This is with both packing and duct tape.

    Jason says these passed the test! The first pic is white base and.the second is Ruby IC base.

    Two thinged we believe led to the original failure and question...
    The ambient humidity and coolness of the aluminum surface led to trapped moisture in the base coat. The evidence was the blush in the ruby IC.
    On these successful parts, I warmed the aluminum part over an oil filled radiator then base coated.

    Unfortunately, I can't do anything about working in the oitdoor ambient environment.  I will just have to control the parts and times I am working.

    Thank you to Jason for the long text  message tutorials. Love your products and service!

    Now, I wonder if I can touch up those cross hatches? LOL
  • WileECoyoteWileECoyote Posts: 7,042Member, Moderator, Business Ninja El Moderator
    Spinner said:

    I did another adhesion te test. (That is such a hard thing to do on a good looking part!)

    And this is why no one wants to do it, but look at how much information you got out of it.
  • LibertymanLibertyman Posts: 967Member, Business Ninja ✭✭✭✭
    @Spinner we try and spray our stuff early in the morning and stay away from doing it in the afternoon when it's hotter and more humid. That seems to help a lot. We're in Minnesota and it definitely gets muggy that's for sure. Spraying in an unconditioned booth sucks when it's humid. Yesterday it was 102 here with the humid level through the roof just decided to close up shop and go to the cabin and drink cold ones. Also thanks for the read, very through, and informative.
  • SpinnerSpinner Posts: 235Member ✭✭✭
    Yeah, that particular day was crazy humid. I shouldn't have even tried, but now I know.
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