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What can you mix with epoxy so that it thins out but still maintains its holding properties to allow you to inject it into hairline cracks?

Thanks
 
Posts: 133 | Location: Southeast | Registered: 18 July 2007Reply With Quote
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Acetone


John Farner

If you haven't, please join the NRA!
 
Posts: 2939 | Location: Corrales, NM, USA | Registered: 07 February 2001Reply With Quote
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I've found a trick to use with Acraglas. It may work with other epoxies. Spread a bead of Acraglas on the crack, heat it with a hair dryer. In a couple of seconds it will change to the consistancy of water and flow into the crack. Needless to say, have some paper towels ready for the part that rolls down the stock instead of in the crack. Repeat as necessary. If you think none entered the crack, clamp the stock and watch it boil out of the crack.


Mark Pursell
 
Posts: 544 | Location: Liberty, MO | Registered: 21 January 2003Reply With Quote
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They also offer a laquer thinner that is made to thin epoxies; I use it a bit. Also, you may want to consider using compressed air to force the stuff into the crack.


Jim Kobe
10841 Oxborough Ave So
Bloomington MN 55437
952.884.6031
Professional member American Cusom Gunmakers Guild

 
Posts: 5506 | Location: Minnesota | Registered: 10 July 2002Reply With Quote
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Thanks, if you use the acetone or laquer thinner are you just adding a few drops at a time until you are at the consistency you want?
 
Posts: 133 | Location: Southeast | Registered: 18 July 2007Reply With Quote
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A gunsmith I used to work for would use Acraglass and then use an air compressor to "push" the Acraglass into the crack. He had great luck with this method.
 
Posts: 1658 | Location: Colorado, USA | Registered: 11 November 2002Reply With Quote
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You also can take a hair dryer or similar het wood till its warm. Apply thinned epoxy and cover crack with waxed paper or non stick material. As wood cools it will suck epoxy deep into crack.


kk alaska
 
Posts: 950 | Registered: 06 February 2003Reply With Quote
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quote:
Originally posted by Jim Kobe:
They also offer a laquer thinner that is made to thin epoxies; I use it a bit. Also, you may want to consider using compressed air to force the stuff into the crack.


Jim, Wouldn't that epoxy thinner that is made to thin laquer be better? dancing
just had to! Wink
 
Posts: 2357 | Location: KENAI, ALASKA | Registered: 10 November 2001Reply With Quote
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Remember this when using Epoxy , certain ones don't use standard Thinners !. The ones which work on some are not obtainable by the general public .

Altering epoxy isn't like thinning Polyester ISO or Monomer resins ( Fiberglas Resin ) Which can be done with monomers or small quantity's of MEK or Acetone .

I now post a Direct response to this very question from " West Systems " .

At this point I want to make it PERFECTLY CLEAR that not all epoxies are the same there formulas vary Greatly . Experimenting is advisable > IMO !!.

A question frequently posed to our technical staff is "can I thin West System epoxy so it will flow or penetrate better?" The answer to that question is "yes, but not without consequences." Many of the advantages of thinning epoxy are offset by disadvantages in other areas of epoxy performance.

Thinning epoxy means lowering its viscosity. Low viscosity epoxy flows better, is easier to roll or brush, saturates fiberglass fabric quickly, and penetrates more deeply and more easily into porous surfaces like partially rotted wood. There are two methods of temporarily thinning epoxy. One is to heat the mixture and the other is to add solvent to the mix. The goal of both methods is to reduce the epoxy's viscosity. This article explains what happens to West System epoxy when it is thinned either by heating the components or adding solvent to the mixture.

Through knowledge gained from our comprehensive test programs and from 30 years of practical experience, we have learned that epoxy formulation is a balancing act. When one characteristic is altered-e.g. changing handling attributes by adding a volatile solvent-other characteristics like moisture resistance and strength are also changed. Our chemists formulate a well balanced, versatile epoxy that provides excellent structural strength and moisture resistance. If you elect to modify it, you become an epoxy formulator and need to understand the effects of your changes. Armed with the information in this article, you can decide if thinning epoxy is worth the tradeoff in performance.

Is thinning necessary?
There is a perception that epoxy needs to penetrate deeply into wood to be effective. Sometimes this is true, but most of the time it is not. Some common misconceptions are that deep penetration of epoxy 1) makes rotted wood as strong as new, 2) increases adhesion, and 3) makes wood more waterproof. The following is a brief discussion of these points.

You may finish the article at the following link .

http://www.seqair.com/skunkworks/Glues/WestSystem/Thinning/Thinning.html


Shoot Straight Know Your Target . ... salute
 
Posts: 1738 | Location: Southern Calif. | Registered: 08 April 2006Reply With Quote
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quote:
Originally posted by Dr.K:
Remember this when using Epoxy , certain ones don't use standard Thinners !. The ones which work on some are not obtainable by the general public .

Altering epoxy isn't like thinning Polyester ISO or Monomer resins ( Fiberglas Resin ) Which can be done with monomers or small quantity's of MEK or Acetone .

I now post a Direct response to this very question from " West Systems " .

At this point I want to make it PERFECTLY CLEAR that not all epoxies are the same there formulas vary Greatly . Experimenting is advisable > IMO !!.

A question frequently posed to our technical staff is "can I thin West System epoxy so it will flow or penetrate better?" The answer to that question is "yes, but not without consequences." Many of the advantages of thinning epoxy are offset by disadvantages in other areas of epoxy performance.

Thinning epoxy means lowering its viscosity. Low viscosity epoxy flows better, is easier to roll or brush, saturates fiberglass fabric quickly, and penetrates more deeply and more easily into porous surfaces like partially rotted wood. There are two methods of temporarily thinning epoxy. One is to heat the mixture and the other is to add solvent to the mix. The goal of both methods is to reduce the epoxy's viscosity. This article explains what happens to West System epoxy when it is thinned either by heating the components or adding solvent to the mixture.

Through knowledge gained from our comprehensive test programs and from 30 years of practical experience, we have learned that epoxy formulation is a balancing act. When one characteristic is altered-e.g. changing handling attributes by adding a volatile solvent-other characteristics like moisture resistance and strength are also changed. Our chemists formulate a well balanced, versatile epoxy that provides excellent structural strength and moisture resistance. If you elect to modify it, you become an epoxy formulator and need to understand the effects of your changes. Armed with the information in this article, you can decide if thinning epoxy is worth the tradeoff in performance.

Is thinning necessary?
There is a perception that epoxy needs to penetrate deeply into wood to be effective. Sometimes this is true, but most of the time it is not. Some common misconceptions are that deep penetration of epoxy 1) makes rotted wood as strong as new, 2) increases adhesion, and 3) makes wood more waterproof. The following is a brief discussion of these points.

You may finish the article at the following link .

http://www.seqair.com/skunkworks/Glues/WestSystem/Thinning/Thinning.html


Shoot Straight Know Your Target . ... salute


Good thing he is not Building a Boat thumb
 
Posts: 2357 | Location: KENAI, ALASKA | Registered: 10 November 2001Reply With Quote
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I used to formulate Epoxy's !. Boy that's Funny good thing he's not building a boat !.

I have built several Boats my self , 9 wooden , Dozens of Fiberglass , 4 epoxy carbon fiber racing class and 1 Aluminum Trimaran 90 Ft..

While I was in High school I worked for a Boat builder . Weekends after school summer vacation ?( Never had one ).

We built Sanger, Kona ,Day cruisers,Hawaiian and a couple that escape memory . I repaired MANY Chris Craft all makes and models .The Man I worked for, Grandfather Owned or ran the Chris Craft yard up Newport Beach area CA. !.

I also helped restore a 3 masted Brigantine which I also crewed too the Marquesas Islands, where the Owner sold her .

I built custom homes after my Stint with the Army , I was trained as a Ships carpenter however .
All the while putting myself through college .

One of these days I'll start scanning some old pictures so as to Post , To back up my know it all boasting . There were no Home computers or digital photography or hand held calculators back then .

Just sweat mussel tears an a Slide Rule . Eeker




This is the Mintar 48 I built in 1976 for a customer . Bicentennial all wood . Including Eucalyptus Spotted Gum , Teak ( Thailand Teak ) Greenheart ,Mahogany ,Turpentine Crows Ash .

I've got near 60 kodak 140 Slide Carousel's full and literally Boxes of ? near Every picture I ever taken . Most in slides some funky faded 35mm color & Black & White photos and some SUPER SHARP 35mm photos .

See
I've been around the block several times .

Yet still don't know it all an never will !!.

Shoot Straight Know Your Target. ... salute
 
Posts: 1738 | Location: Southern Calif. | Registered: 08 April 2006Reply With Quote
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Dr. K,
Part of my concern with thinning was reducing the adhesion or strength properties of the expoxy. I think the warming the area of the crack and applying the epoxy to the area after warming should work on the hairline crack that I am trying to repair. Thanks for the info.
 
Posts: 133 | Location: Southeast | Registered: 18 July 2007Reply With Quote
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I added a little transtint to some good 3-hour epoxy to see if I could tint it wood-color. well I added too much and it was nearly black. it did not cure as quickly as an untinted sample did. I next used chestnut ridge stain to do the same, it took a fair amount to get the color, the epoxy did thin, and it took 3x as long to finally harden.

I didn't bond anything with the samples so I can't speak to the strength.

FWIW.
 
Posts: 1064 | Registered: 04 January 2005Reply With Quote
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These are numerous sources for pigments Dyes .Here is just a couple . Automotive Marine Aerospace painting suppliers also use these colorants to .

http://www.brownells.com/aspx/NS/store/catsearch.aspx?k...aglass&ps=10&si=True

http://www.pigments.com/?gclid=CJeTva3YoZQCFSEbagodyGyWtw

http://www.jamestowndistributors.com/userportal/main.do


http://www.mrfiberglass.com/color_pigments.html

http://www.earthpigments.com/?gclid=CIr1jazToZQCFSoZagodFEOPtQ

http://www.revchem.com/supplies.html

http://www.spectrumcolor.com/default.asp

Remember to ask for " PIGMENT ONLY " . Solvent dispersion type ( NOT Water based )

You don't want GelCoat as it's Polyester based resin with pigment added unless your using Acraglass then it would be ok . However that's highly unlikely one would buy gelcoat for Stock Work !.

Shoot Straight Know Your Target . ... salute
 
Posts: 1738 | Location: Southern Calif. | Registered: 08 April 2006Reply With Quote
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