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73-87 Chevy _ GMC Trucks => Body, Glass & Paint => Topic started by: hogwild on January 27, 2008, 12:04:45 am

Title: primer wont sand
Post by: hogwild on January 27, 2008, 12:04:45 am
primed my truck last weekend with endura intermix 3to 1 epoxy primer, went to sand it today and it wont sand , it just plugs up paper and makes gouges.it doesnt matter what grit it use either. what now ?. reprime over it with different primer?
Title: Re: primer wont sand
Post by: Redneckchevy on January 27, 2008, 12:06:23 am
sounds like u might of mixed it wrong......I wouldnt repaint over it...Or the new primer will be floating...im pretty sure the bad stuff will have to come off....
Title: Re: primer wont sand
Post by: hogwild on January 27, 2008, 12:14:26 am
wana buy a truck? . how am i to get it of wont sand. some kind of stripper?
Title: Re: primer wont sand
Post by: JRConnieK10 on January 27, 2008, 12:20:02 am
Maybe try to wet sand an area first.
Title: Re: primer wont sand
Post by: Redneckchevy on January 27, 2008, 12:24:07 am
Was it mixed to specs? or eye balled?
Title: Re: primer wont sand
Post by: hogwild on January 27, 2008, 12:25:52 am
we mixed it dead on to specs  , 3 to 1
Title: Re: primer wont sand
Post by: HAULIN IT on January 27, 2008, 12:29:26 am
Hogwild, I'm familiar with paints/primers, ect. (I own a body shop) however I'm not familiar with the Endura products. Epoxy products come in many different make-ups for different jobs. Some are used primarily for adhesion to bare metal, these do not sand very well usually, others can be epoxy based filler type primer, which should sand fairly well after drying. Did you get a product data sheet on this primer when you bought it? It may not be intended for the way you are using it or as mentioned, maybe something is mixed wrong (incompatible products, ect.) Don't panic yet! Read up on how it is described on the directions & post, We will try to help. Lorne
Title: Re: primer wont sand
Post by: Redneckchevy on January 27, 2008, 12:30:30 am
see im thinking its soft and wet...Epoxy primer should not gouge that easy...Its epoxy it should be hard......Maybe u should call the pepole that make it...maybe they would have better advice then to strip it down...
Title: Re: primer wont sand
Post by: hogwild on January 27, 2008, 12:35:42 am
 went to endura site , and it says intermix 3-1 primer is for sand blasted steel , says nothing about sanding it . i dont have instructions, primer was left overs that i had from painting a trailer.
Title: Re: primer wont sand
Post by: Redneckchevy on January 27, 2008, 12:48:35 am
Could it of gone bad?
Title: Re: primer wont sand
Post by: hogwild on January 27, 2008, 01:00:22 am
its only 1 month old , and its suposed to be good for one year after opening, maybe it needs to cure longer , but i thaugt a week should be lots of time
Title: Re: primer wont sand
Post by: Redneckchevy on January 27, 2008, 01:01:41 am
ok i got ya...But what temp are u curing it at??
Title: Re: primer wont sand
Post by: hogwild on January 27, 2008, 01:15:27 am
24HRS AT 20 than it went out side at about -15 for 4 days then back in shop for 2 days at 15-20 c
Title: Re: primer wont sand
Post by: zieg85 on January 27, 2008, 07:37:50 am
Epoxies stop curing at 50 degrees F.  They all do. 
Title: Re: primer wont sand
Post by: Blazin on January 27, 2008, 07:51:06 am
In my experience if the sander speed is to high epoxies tend to smear, instead of sand.
I agree some epoxy primers are not meant to be sanded. They are meant to be topcoated within a few hours of application.
 You might have to strip it off with heavy paper or stripper.
Title: Re: primer wont sand
Post by: choptop on January 27, 2008, 03:50:56 pm
Hey Zeig85, 15-20 C is 59-68 degrees F. I think you missed that like I did the first time I read it, I almost fell over. I do know that temperature and humidity make a difference on some paints. does endura have any ideas?
Title: Re: primer wont sand
Post by: hogwild on January 27, 2008, 04:46:49 pm
notice i had it out side for 4 days, maybe it froze ?. i have it in shop with heat cranked  mabe it will harden with some luck.what should i use for second primer coat when i and if i get this stuff sanded
Title: Re: primer wont sand
Post by: hogwild on January 27, 2008, 07:30:08 pm
went back to shop tonight and tryed sanding again , seems to be getting better . im now thinking it just needs to cure more.
Title: Re: primer wont sand
Post by: zieg85 on January 28, 2008, 06:58:08 am
Time and temp is the big deal.  Did the epoxy call for an induction or sweat in time?  If it did and you didn't do it that would also cause it to be soft.  I have been in the paint field for 23 years, I have seen quite a bit
Title: Re: primer wont sand
Post by: HAULIN IT on January 28, 2008, 08:57:51 am
Hogwild, I'm concerned about the 24 Hrs. @ 58-68F, then put outside. These chemicals work best in more stable climate. If you were "on the edge" of 50F, as Zeig says "your in trouble". 24 Hrs. above curing is pushing it. It goes outside below freezing, nothing is curing at this point. Now back inside, if over 50 F it's thinking about curing again. Kinda like putting on only new underware & going out in the cold for a while & coming back in. It is better once your inside, but the damage may already be done. Good Luck, Lorne       
Title: Re: primer wont sand
Post by: Redneckchevy on January 28, 2008, 09:23:45 am
Dont think i could of put that any better lol .But how would he go about getting it off...Just curious lol cause im thinking Media blasting it.....or a nasty chemical striper.
Title: Re: primer wont sand
Post by: zieg85 on January 28, 2008, 09:28:42 am
The epoxies I work with are fine if the temp is raised so it will finish curing (If the sweat-in or induction time) was followed if required.
Title: Re: primer wont sand
Post by: HAULIN IT on January 28, 2008, 10:16:31 am
Zeig, What company are you working with? Just curious who's got what going on. Thanks, Lorne
Title: Re: primer wont sand
Post by: zieg85 on January 28, 2008, 10:25:15 am
I am a Technical Service Rep for The Sherwin-Williams Co.
Title: Re: primer wont sand
Post by: hogwild on January 28, 2008, 09:05:45 pm
all this talk is over my head, primer i used is endura intermix 3-1. check out their web site and see what you think, endurapaint.com. going out side with nothing but underwear would not have mattered , today were i am from  , it is -39 deg celcius your balls freeze underwaer or not. they dont call it the great white north for nothin !. no induction time is required  can be top coated from 1 hr - to 14 days is what web site says
Title: Re: primer wont sand
Post by: HAULIN IT on January 28, 2008, 09:41:38 pm
Hog, Your talking 40 degrees below freezing? WOW! How do you keep your house, garage warm? That's a long way from comfortable. I bet your vehicles make all kinds of odd noises & funny habits when you start out in the mornings. I don't think anything  short of a polar bear would like that weather. Good Luck with your project, Lorne
Title: Re: primer wont sand
Post by: hogwild on January 28, 2008, 09:48:30 pm
haulin , real good heaters, and yes 40 below 0 not a misprint . its not always this cold , normal is about minus 10
Title: Re: primer wont sand
Post by: zieg85 on January 28, 2008, 10:11:40 pm
all this talk is over my head, primer i used is endura intermix 3-1. check out their web site and see what you think, endurapaint.com. going out side with nothing but underwear would not have mattered , today were i am from  , it is -39 deg celcius your balls freeze underwaer or not. they dont call it the great white north for nothin !. no induction time is required  can be top coated from 1 hr - to 14 days is what web site says
Talking in general terms...  Items I picked up on the data sheet that leads me down the thought process.  This is a unique primer system with the long potlife versus fast cure tendencies if the directions/temps are followed.  Typically when there is a statement about minimum temp. of the paint when mixed that is around the minimum required to cure.  Also this is a primer designed to go on fairly thick.  If it is applied at a thinner film, like a sealer would be, cure would also be slowed down.  If it were me I would give it time to cure when the temps get more in line it should cure.  Sandability is a good test for cure as well as a strong solvent to rub the coating lightly to see if it is still soft.  My $.02
Title: Re: primer wont sand
Post by: loudnlow87 on February 04, 2008, 11:08:40 pm
ultimately temp shouldnt matter terribly for epoxy primer; it cures by a chemical reaction, not air drying. ive sprayed epoxy primer inside then had to put it outside, maybe 25F and light hail. i could still smell it curing a week later but it was fine. and i drive it everyday.
Title: Re: primer wont sand
Post by: hogwild on February 04, 2008, 11:27:15 pm
well some time has passed now ,and it appears i set off a false alarm, primer just needed to be inside warm shop to cure more. it sands fine now. cold didnt seem to do anything but slow curing proses. thanks for your help & i am sure i will need more as project  progreses. painting a truck is deffenetly a learning process. how the%*$%*& do you spell proses ???
Title: Re: primer wont sand
Post by: Redneckchevy on February 05, 2008, 12:23:50 am
 process....glad u got it fixed tho! was worried u would have to strip it