Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations waross on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  • Users: avior
  • Order by date
  1. avior

    Concrete Crack Sealant required

    English or French . . . PhD University of Illinois and MS Université de Montréal.
  2. avior

    Concrete Crack Sealant required

    hemis, Contact him to know more about "self healing materials": http://www.polymtl.ca/recherche/rc/professeurs/details.php?NoProf=294
  3. avior

    Concrete Crack Sealant required

    I knew a guy from Ecole Plytechnique du Montreal who showed me a “self healing material”. There are micro spherical resin bubbles imbedded and also solid catalyst crystals uniformly distributed inside. When crack develop the bubbles hit by the crack will bleed and liquid resin in contact with...
  4. avior

    Phenolic Composites Manufacturing - Autoclave Cure

    We are curing phenolic/aramid prepreg parts in oven under vacuum and autoclave under 15, 30 and 45 psi pressure since 2003 and glass phenolic since 2006. No important problems occurred. Few bags puncture from time to time due to bridging or vacuum ports sliding during manipulation. Reusable...
  5. avior

    Metal bonding issues

    I have to tell you that I received four plates phosphoric anodized, I bonded them in the same conditions, same material, all samples had high peel results, |I was able to reach 89 pound per linear inch . . . it may be sulphuric anodized surface not appropriate to bonding, I just had luck with...
  6. avior

    Metal bonding issues

    I'm measuring primer thickness using elcometer 345 probe. On flat, bare metal panels primer tickness is between 0.15 mils and 0.17mils, that is actual paint gun setup. On anodized panels I can't measure the thickness because of anodized layer, even to make “0” is impossible, the error is around...
  7. avior

    Metal bonding issues

    What I see is that each strip that fails - has between .040-.090” cohesive failure at the very beginning and than changes to adhesive failure within next .020”. I just checked bonding thickness, it seems to be .003-.005” almost uniform on each sample. Carrier I used mat and knit (knit tested in...
  8. avior

    Metal bonding issues

    Cohesive failure, adhesive on both surfaces in high results. On the others samples it looks like primer doesn't stick on the anodized surface, the strip is clean, primer traces on it, most of the primer and all adhesive is on the outer strip . . . like release agent was used instead of anodize...
  9. avior

    Metal bonding issues

    I'm trying to bond two 17”x17” aluminum plates with 3M AF163-2 structural adhesive. The plates are modified sulfuric acid anodized, primed with 3M EC 3960 adhesive primer within 4 hrs. after anodization , adhesive film applied and cured 250F/ 45psi 90min. Lap shear test per ASTM D1002 gives...
  10. avior

    Prepreg tack standard test?

    We have a receiving procedure (maybe not the best) for tack test preinpregnated cloth: - clean a steel plate using a solvent (M.E.K.) and dry it. -cut the specimens of prepreg 2" by 2", apply the specimen to the plate using light hand pressure, remove the backing film, apply a second specimen on...
  11. avior

    How to repair a composite mold

    But this is carbon fiber reinforcing thermoplastic resin, our mold is carbon-thermoset resin (epoxy)
  12. avior

    How to repair a composite mold

    A carbon – epoxy mold .200” thick was donated by an aeronautical composite manufacturer (we don't know exactly what resin and tissue was used to manufacture the mold). This mold has a .250” hole machined throw. We intend to laminate few parts (8-10) from fiberglass epoxy 350F autoclave cure...
  13. avior

    mixing solvent with uncured epoxy resin

    Thanks for your answer, . . . indeed I was waiting a reply from compositgeek or compositepro. As far as I know any solvent isn't a proper diluent for epoxy, but since an important industrial use for acetone involves its reaction with phenol for the manufacture of bisphenol A, I hope that may...
  14. avior

    mixing solvent with uncured epoxy resin

    I know some of you have a strong background in chemistry. In our reparation process we are using Epocast 50A two component epoxy resin ( http://korsil.ru/pdf/50A1-946(US).pdf ). The resin has very good laminating properties but is too viscous to inject it with a syringe needle. May I add a few...
  15. avior

    Does bleeder use is important?

    During my last stage I was surprised to notice that bagging sequence learned at school (prepreg layup – oven/autoclave cure) is not exactly the same that is used in all aeronautic shops. More, now I saw a few of the same parts bagged without bleeder. Does it means that bleeder use is optional...
  16. avior

    Materials and Processes Specification

    A change just arrived, was: - Shop life - 40 dasys is: - Shop life - out time 15 days, mechanical life 40 days what means "mechanical life 40 days"?
  17. avior

    May resin puncture the bag during cure cicle?

    From time to time vacuum leak occure during autoclave cure cicle. Sometimes because bag bridging, or seal compound sliding or vacuum port bridging the bag crash, and sometimes unknown reasons. When inexpilcable bag puncture arrive we chalk it up against resin. I heard that during gelation...
  18. avior

    silicone rubber sponge

    I have a roll of silicone rubber sponge sheeting .150 AMS 3195 since ’99. I’m surprised to find that my sheet is curved and I need it plane to use it. Do you know any trick to make it strait (temperature, pressure, etc.)?
  19. avior

    Best composite material for gasoline tank

    In D.Gay, S.V.Hoa, S.W.Tsai ’s book “Composite materials - Design and application”, at page 172 speaking about efficiency they recommend kevlar/epoxy against glass/epoxy. More, in chapter 18.1.8 they calculates the stress, strain, etc. considering a thin tube under pressure made by filament...
  20. avior

    Sandwich, epoxy

    Try: ASTM C297 - Tensile strength of flat sandwich construction in flatwise plane, ASTM C393 - Flexure test of flat sandwich construction, ASTM D635 - Burning, ASTM D1781 - Climbinmg drum peel test for adhesion, ASTM D3418 - Glass transition by DSC + ASTM E1356 - Assignment of Tg, or ASTM...
Back
Top