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Thinning Epoxy Resin - 8/8/2005 4:52:00 PM   
chelapa


 

Posts: 62
Joined: 1/28/2005
From: , NY, USA
Status: offline 		Hi folks. long time i havnt posted. if im getting some pin holes in the lamination, i think a good way to solve it would be thinning out the epoxy a bit. yes or no?
       Post #: 1

RE: Thinning Epoxy Resin - 8/8/2005 5:13:11 PM   
Ed Smith


 

Posts: 2820
Joined: 12/29/2001
From: Brantford, ON, CANADA
Status: offline 		NO!. Do not thin epoxy resin when laminating. The resin may not cure properly, The part may cure but be rubbery, the physical characteristics of the cured epoxy will be changed, never for the better.

If not painting in the mold with either color or clear it is almost impossible to be completely free of pinholes. To try and prevent them I lay in a first layer of 1-1 1/2oz cloth. The finer weave does help. This first layer has to be really wet with excess resin. My second layer is usually 6oz cloth and will soak up the excess resin with very little needed to be added. After that then do what you do.

Ed S

(in reply to chelapa)
       Post #: 2

RE: Thinning Epoxy Resin - 8/8/2005 5:24:24 PM   
chelapa


 

Posts: 62
Joined: 1/28/2005
From: , NY, USA
Status: offline 		I'll try that tonite. thanx! =)

(in reply to Ed Smith)
       Post #: 3

RE: Thinning Epoxy Resin - 8/10/2005 12:27:18 AM   
moldmaker


 

Posts: 84
Joined: 11/10/2004
From: lexington, TN, USA
Status: offline 		The best way to get rid of pin holes is to mix epoxy with cabosil making a very thin mixture just enough so it will not run on verticle sides Paint the mold and let it set until hard . Then lay up part will be pin hole free

(in reply to chelapa)
       Post #: 4

RE: Thinning Epoxy Resin - 8/10/2005 1:00:23 AM   
davidfee



Posts: 691
Joined: 6/21/2003
From: San Diego, CA, USA
Status: offline 		That works, of course, but it's a heavy solution. Using a very light layer of glass works just as well, and provides some structure.

(in reply to moldmaker)
       Post #: 5

RE: Thinning Epoxy Resin - 8/10/2005 3:01:41 AM   
moldmaker


 

Posts: 84
Joined: 11/10/2004
From: lexington, TN, USA
Status: offline 		Not as heavy as a light layer of cloth and you can still get pin holes even with a two ounce cloth . Try it before you knock it

(in reply to davidfee)
       Post #: 6

RE: Thinning Epoxy Resin - 8/10/2005 6:20:48 AM   
davidfee



Posts: 691
Joined: 6/21/2003
From: San Diego, CA, USA
Status: offline 		Ok, I see that you disagree with me. That's ok. I've tried a great many things, including what you suggested. I've found that using a layer of 0.6oz glass gives more repeatable results, with less weight gain. And it's adding fibers (strength) instead of just resin.

I like to make my layups pretty dry, as my goal is maximizing strength and stiffness, while minimizing weight. Cosmetics are also important. The layer of light glass works for me. I never said two ounce... I'm talking 0.6oz-1oz. I guess "very light cloth" is a relative term.

-David

(in reply to moldmaker)
       Post #: 7

RE: Thinning Epoxy Resin - 8/10/2005 12:21:42 PM   
RAPPTOR


 

Posts: 168
Joined: 12/10/2001
From: WELLINGTON, FL, USA
Status: offline 		YOU CAN THIN A GOOD GRADE EPOXY.. NOT WEST ,ITS RUBBER ,AND SOFTENS IN THE SUN,, THEY SELL EPOXY THINNER,GO FIGURE!! ACETONE OR MEK WORKS ALSO.. NEVER SEEN AND SIDE EFFECTS,, USE ZAP FINISHING RESIN FOR SMALL LAY UPS.. WORKS SUPER.. SPRAY RESINE ON YOUR MOLDS,LET IT TACK UP OR DRY.. THEN LAY ON CLOTH.. I LIKE DRY BETTER,CLOTH SLIDES AROUND EASIER..DONE HUNDREDS LIKE THIS ..GO TO VYNALESTER RESIN ,,ITS THE BEST,,RD

(in reply to chelapa)
       Post #: 8

RE: Thinning Epoxy Resin - 8/10/2005 5:30:29 PM   
moldmaker


 

Posts: 84
Joined: 11/10/2004
From: lexington, TN, USA
Status: offline 		Raptor I have been thinking about trying vinylester resin tell us more about it .
s it compatible with epoxy molds ? Also what mold release system do you use ?

(in reply to RAPPTOR)
       Post #: 9

RE: Thinning Epoxy Resin - 8/10/2005 10:37:06 PM   
goony


 

Posts: 120
Joined: 1/18/2003
From: peterborough, UNITED KINGDOM
Status: offline 		ive been trying to promot this resin but no won cares Just use it as you would a polyester resin


goony

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       Post #: 10

RE: Thinning Epoxy Resin - 8/12/2005 12:47:15 PM   
RAPPTOR


 

Posts: 168
Joined: 12/10/2001
From: WELLINGTON, FL, USA
Status: offline 		HI GOONY IS RIGHT.. USE AS AS POLYESTER.. LOOKS THE SAME..THE STUFF IS SUPER.. I HAVE GONE TO AS LITTLE AS 1/4 PERCENT HARDENER WITH GOOD RESULTS..GIVES ME MORE WORK TIME.. 1/2 WOULD BE BEST IF YOU ARE IN A COOL AREA.. OK,,SANDS SUPER,NO TACKY SURFACE, HEAT DOES NOT EFFECT IT,, ANY GLUE STICKS TO IT CA,EPOXY,ECT..CAN BE THINNED WITH ACETONE,MEK,..CAN AD COLOR,PIGMENT,,,WORKS WITH ALL RELEASE SYSTEMS..PVA,WAX.MARBACOAT.SILICONE..HAS JUST THE RIGHT AMOUNT OF FLEX SO THE GLASS DOES NOT ,EGG-SHELL, WHEN FLEXED,, IT TOOK ME A LONG TIME TO FIND A RESIN I COULD RELY ON,,THIS IS IT,,ABOUT $32 A GALLON RD

(in reply to goony)
       Post #: 11

RE: Thinning Epoxy Resin - 8/14/2005 6:55:21 AM   
chelapa


 

Posts: 62
Joined: 1/28/2005
From: , NY, USA
Status: offline 		BUT SMELLS BAD!

(in reply to RAPPTOR)
       Post #: 12

RE: Thinning Epoxy Resin - 8/14/2005 12:53:31 PM   
Ed Smith


 

Posts: 2820
Joined: 12/29/2001
From: Brantford, ON, CANADA
Status: offline 		AND IT IS DANGEROUS. ONE DROP OF THE HARDENER IN THE EYE AND IT IS OVER. IT CANNOT BE WASHED OUT QUICKLY ENOUGH. POLYESTER RESINS SHOULD NOT BE ALLOWED IN A DOMESTIC ENVIRONMENT.

Ed S

(in reply to chelapa)
       Post #: 13

RE: Thinning Epoxy Resin - 8/14/2005 6:24:01 PM   
goony


 

Posts: 120
Joined: 1/18/2003
From: peterborough, UNITED KINGDOM
Status: offline 		if you use the cat dispensers properly you couldnt get it in youre eye? unless you were REALLY THICK? and no more dangerous than cyano!

if you put it on a scale of water being 0 and epoxy being 100 then vinylester would be 95and you dont have to weight 24 hours to crack it out or need to post cure it to get the best results you can gel it lay it up and crack it out half an hour later

goony

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I often land inverted

(in reply to Ed Smith)
       Post #: 14

RE: Thinning Epoxy Resin - 8/15/2005 8:10:38 PM   
RAPPTOR


 

Posts: 168
Joined: 12/10/2001
From: WELLINGTON, FL, USA
Status: offline 		YOU SHOULD ALLWAYS WARE GLASSES AND GLOVES!! OH YA. THINS WITH STYRENE ALSO 10% RD

(in reply to goony)
       Post #: 15

RE: Thinning Epoxy Resin - 8/15/2005 10:48:21 PM   
Ed Smith