epoxy paint filler additives

Discussion in 'Materials' started by valvebounce, Jun 21, 2012.

  1. Angélique
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    Angélique aka Angel (only by name)

    The same FAQ as above tells why, and how this can be minimised:
    Cheers,
    Angel
     
  2. pauloman
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    pauloman Epoxy Vendor

    bntil - the solvent free 'epoxy paints' and similar are often used with fiberglass cloth for structural repairs in chemical plants, refineries, piers, piling etc. It is very common. After 20 years in the epoxy business and lots of boat behind me, i would have no problem building a boat with any of the solvent free epoxy paints I stock and sell, they are just typically more expensive than the marine epoxy systems due to the extra processing and additives involved ( and generally less brittle). Some discount marine epoxy vendors simply repackage the raw resin and curing agents from the big chemical companies, but the serious marine epoxy vendors those those raw materials and then 'formulate' then for certain properties and some become marine epoxy and others become epoxy paint or epoxy putty.

    There was also a few posts on post curing....

    some epoxies, especially high temp epoxies, are a bend of curing agents that have different min temps needed to begin the crosslinking of part A and part B. So, some (all?) high temp epoxies are a bend of ambient curing agents and curing agents that require say 150 degrees to begin crosslinking. The first curing agent sets up at normal temps. Then you do a post cure to get the other curing agents to crosslink. We once developed an epoxy for use down oil well rigs that would not begin to set until temps were about 150 f - giving it time to get to the bottom of the hole.

    Epoxy curing is a chemical reaction and like all chemical reactions it happens quicker at higher temps. that said, after all cross linking has occurred (at whatever temp) - raising the temp doesn't add anything. Note that complete crosslinking (ie. curing) of epoxies can take a week plus and raising the temp during that process will speed it up, but that is not the same as post cure. yes, epoxies will soften at about 140 F but will get harder again as they cool back down.


    Bntil - yes some epoxies are suited for different uses. - I wouldn't want to use most/any of my marine epoxies to do a fiberglass cloth emergency underwater repair on a sinking boat, - it wouldn't work, but my underwater epoxies do this sort of thing all the time. It is still just basic epoxy chemistry using different curing agents with different interactions with water/moisture.

    paul oman
    progressive epoxy polymers, inc
     
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  3. goodwilltoall
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    goodwilltoall Senior Member

    Dave C (former paint chemical engineer) who's now dead, but periodically wrote in MAIB recommended lime for filler, it probably a varient of talc, comes in 50lbs bags for about $10.00.
     
  4. mydauphin
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    mydauphin Senior Member

    I find most products priced according to their benefit. Cheap epoxies have undesirable qualities, more expensive ones are more reliable. That said, I buy epoxies from $20 a gallon to $100 a gallon, clear, fast cure, slow cure, water based, 5 to 1, 2 to 1, 1 to 1.... They are all different, all different strengths and weakness. Different temperature performance and UV resistance. I have one epoxy that takes 1200f that I use for exhausts. I have one that is flexible at room temperature that I used for wiring covers.
     
  5. mydauphin
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    mydauphin Senior Member

    Talc is more inert than lime. Lime is like concrete, and is alkaline. I have used clean dry sand to build indestructible mixes. Strong as steel almost impossible to sand. Best mix I use is previously sanded epoxy and fiberglass leftovers. Better than anything you can buy and it is free.
     
  6. PAR
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    PAR Yacht Designer/Builder

    It's difficult to make generalities about fillers. Lime isn't a material I'd employ, though talc is used by everyone. Milled 'glass fibers are also used by everyone, usually referred to as "liquid 'glass". It's the main ingredient when making 'glass bonds for me. Most filler mixtures will have multiple materials, to get the physical and viscosity qualities desired, for the tasks and conditions at hand.
     
  7. pauloman
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    pauloman Epoxy Vendor

    the old Splash Zone A-788 is the grand daddy of underwater epoxies - thick like chewing gum. Not sure of the fillers in it, but it is heavy! It has been the secret trick product used by professional race car mechanics to re-line the cylinders of race cars for decades. That's the power of certain fillers - creating an application that exceeds the limits of the epoxy itself.

    The micro spheres are a byproduct of the conversion of bauxite ore into aluminum.

    we mix sand into the epoxy to make epoxy cement to patch airport runways..

    We sell more of out hydrophobic fumed silica (the most common epoxy thickener, at least with the epoxy manufactures) to fly fisherman than we do to boat builders.

    Our wood flour is a byproduct of the wood mills and our EZ thick (equal to the wood floor) is, I think, a byproduct of the paper mills.



    paul oman
    progressive epoxy polymers, inc.
     
  8. valvebounce
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    valvebounce Senior Member

    Some of the uses for epoxy are amazing,I would never have dreamed at some of it's applications,and additives.
    I do know some engine cylinders are ceramic coated,as are turbos,epoxy coatings and their uses seems endless,obviously a material of the future[and present]
    There has been some great info on this thread
     
  9. mydauphin
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    mydauphin Senior Member

    With Epoxies you can build a spaceship, restore a wooden furniture or build and engine. But a lot of R&D and testing is require and then you have the 787 factor.

    No one can tell you what is going to happen in 30 years to those planes. The some of the epoxy may degrade.

    Among the many things I do with epoxy is art work. There are many artists that use it for paintings, and sculptures. Most serious collectors or aritists won't touch anything in an untested medium like epoxy, they question if it will be around in 100 or 400 years, while bronze, oils and acrylics will.
     
  10. valvebounce
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    valvebounce Senior Member

    Goodwilltoall,Hi,
    the use of Lime instead of talc sounds much more economical,Has it been tested for water resistance over a period of time?
    As a retired Bricklayer I have seen the results of lime in clay bricks,it swells and blows the face of the brick off.I suppose with epoxy resin instead of clay it becomes impervious to water,but does it last?I imagine if it is painted over it just becomes a covered solid.Did "Dave C" have any test results?
     
  11. valvebounce
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    valvebounce Senior Member

    Pauloman,Hi,
    Being a Bricklayer for many years I often wondered if a medium could be found to develop a brick that would be impervious to water,also a usable compound to replace the sand /cement mortar.Concrete doesnt expand and contract the same as brickwork,which is the main reason it cannot replace it.Condensation is also a problem.
    I imagine a building built with epoxy materials would be weatherproof and well insulated.I suppose it would need to be well vented to cope with condensation.
     
  12. valvebounce
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    valvebounce Senior Member

    I would have thought epoxy would outlive oils and acrylics,bronze is another medium altogether.Internal artwork is usually kept at a regular temperature,and doesnt have the weather deterioration factor to contend with.
     
  13. PAR
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    PAR Yacht Designer/Builder

    Most of the problems associated with trying to find alternative building materials, are the costs related to man made materials. For example, you could use something quite strong and light, when mixed in an epoxy matrix, to create a new, bullet proof brick, but the costs per unit will be way more than a traditional brick, even if it is waterproof, freeze proof, etc. Vermiculite is a possibility as are many other materials, but when you count up all the costs, clay and sand start looking a lot better.
     
  14. goodwilltoall
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    goodwilltoall Senior Member

    Greetings,

    Very often the bricks that are impervious to water (dense) and mortars that are to strong or "rich" with cement are the ones that are most vulnerable to structural problems because of their inability to flex or release trapped water which during temperature cycling begins to cause cracks which allows more water to enter and many times leads to extreme structural failure of the system.

    You really cant beat pulverized rock (cement& lime), sand, and fired clay (bricks)for proven cost effectiveness especially when you factor in thermal mass, sound dampening, longevity, fire rating, asthetics; to bad those attributes of masonry are hard to apply on the water.
     

  15. valvebounce
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    valvebounce Senior Member

    You've hit the nail on the head PAR[so to speak]expense will rule out any evolutionary advancement in building.Here in the UK materials seem to have taken a backward step,floor joists are now being made from three sheets of shuttering/sheathing ply on edge,with strips of laths top and bottom.When I first saw them I asked the site manager why they were being used,he said they were anti-squeek.Haha.Timber framed houses are the latest cheepo,they are 3x2" framed,with a brickwork outer skin,the inner skin is fibreboard they are tied together with brickwork ties fastened to the timber.
    Obviously they are "recyclable houses"
     
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