Recent content by MalcolmW


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  1. M

    Why Hasn’t Somebody Built A 3/4 Scale OV-10? Hmmm?

    Hello, berridos; I don't know if anyone has built a 3/4 scale OV-10, however, there is an aircraft which bears some similarity to your wish for a single engine pusher with the same configuration of the OV-10 called the 'Patriot.' I'm not sure if they are still selling kits for this aircraft...
  2. M

    Wanted Aluminum honeycomb flat stock

    Hello, Ir27, George; Sorry I took so long to notice your discussion. I've worked with aluminum honeycomb panels (military, high performance) using adhesive bonding, and the durability is excellent. Unfortunately, the adhesive bonding techniques that were used required significant facilities...
  3. M

    Corrosion Protection Test

    Hello, Tom; I can only speak to 'priming' using chromate conversion or its variations. Normally, once aluminum has been treated with alodine (or chromic acid), it is rinsed with distilled, deionized or filtered rainwater and air dried. Once completely dry (allow twenty-four hours in air)...
  4. M

    Corrosion Protection Test

    Jman Jake; I am most impressed with your testing program. It replaces opinion with hard data, and I'm quite interested in hearing the results. As I mentioned above, I believe that chromate conversion offers corrosion protection, and a good substrate for paint adhesion. All the best, and thank...
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    Corrosion Protection Test

    Hello, I'm not a coatings man, however, I have some experience with aluminum, adhesive bonding and environmental testing which involved surface preparation. It would seem to me that the passivating process that comes from a chromate conversion on the surface of aluminum should offer a very...
  6. M

    Conclusions on Aluminum Adhesive Bonding Tests

    Hello, MichaelValentineSmith & Gary S.; One more trip down the methacrylate (acrylic) adhesive lane - yes, methacrylate adhesives have an excellent reputation for holding up under severe environmental operating conditions, specifically, aluminum truck bodies (assembled using methacrylate...
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    Conclusions on Aluminum Adhesive Bonding Tests

    Hello, Blakmax; re surface preparation: Yes, chromic acid does require an elevated temperature (above 180 F), which puts it out of consideration for the average home builder. As an alternative, the use of alodine will provide a chromate conversion surface (combined with a distilled water...
  8. M

    Conclusions on Aluminum Adhesive Bonding Tests

    Hello, Blakmax, Gary S., and Orion; I just got back from an overseas trip and missed (until today) the fascinating discussion on adhesive bonding. I do find the comments made by Blakmax positive and insightful and agree with him for the most part (the October 3 post). I have emphasized many...
  9. M

    What PSRU Can we Really Trust???

    Bill; I've read your comments a couple of times which gives me reason to believe that you can offer some good advice. The problem is I'm not a mechanical engineer (adhesives and bonding aluminum, now I can do that stuff all day long until your eyes glaze over), and I'm not sure of all the terms...
  10. M

    sheet alu. skin over solid foam core?

    Hello, Starman, Gary S. (it has been a while); I've followed your discussion about bonding an aluminum skin to rigid foam to produce a structural body. This requires some careful engineering to obtain the necessary stiffness and flexural strength (in a wing) to meet the performance...
  11. M


    Hello, I haven't made any long flights, however, I was impressed with this account of a long over-water flight made in a LSA... Sinus Virus and Taurus Motorgliders by Pipistrel The pilot certainly had faith in his aircraft and navigation. Fly safe! MalcolmW
  12. M

    Corrosion Protection Options for Sheet Metal Construction

    Hello, BB; Alodine contains chromate ions (it's a chromate conversion solution, right?), and as such, can be disposed in a similar manner to chromic acid cleaning / conversion solution. This may be more than your need, but should do the trick: Add a strong alkaline (baking soda, lye [sodium...
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    Conclusions on Aluminum Adhesive Bonding Tests

    Hello, Cazador; (is that 'hunter' in English?) as to your question about bonding / joining aluminum to vinyl foam, that is a question about two materials which have quite different coefficients of thermal expansion. With temperature cycling, any adhesive which has a significantly different...
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    Conclusions on Aluminum Adhesive Bonding Tests

    Hello, Gary, Orion; A very interesting discussion of adhesion & bonding agents. First, the curing of adhesives is a chemical reaction and rates of chemical reactions roughly double for each 10 degrees Celsius rise. So, Orion, your comments are on the mark and consistent with my experience...
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    Conclusions on Aluminum Adhesive Bonding Tests

    Hello, Gary; Yes, I saw the same ‘Discovery’ program and was dismayed at the adhesive failure – shouldn’t have happened. However, a point of clarification: The use of ‘scrim cloth’ in structural adhesives has nothing to do with bond thickness or holding the two substrates apart. When...