Epoxy on new panels - Page 2 - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Body - Exterior
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #16 (permalink)  
Old 11-18-2004, 10:34 AM
Member
 
Last photo:
Join Date: Apr 2004
Location: Georgia
Posts: 3,578
Wiki Edits: 0

Thanks: 10
Thanked 61 Times in 39 Posts
Not sure where your getting your information but so far you only have two thing right on everything written about the epoxy:

The 80 grit:-Right
More flexable-Right.

300mils to fill 36 grit? Try 1.2337 Mils it will work better.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #17 (permalink)  
Old 11-18-2004, 05:37 PM
Member
 
Join Date: Jan 2004
Location: Overland park, Kansas burb of KC
Posts: 244
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
I think you missed what I said I use 80 grit on steel when doing filler. 80-180 on alunimum.

NO WAY do you need 36 grit for filler to stick to metal. Take 36 grit to a 2003 Chrysler 300M hood and find out what happens

Since this is painting basic 101 did you know the average OEM paint job is 6-9 mils thick. Roughly the thickness of a paper business card. Most warrentied film thickness is 14 mils, which what PPG suggests as the max thickness for them to warrenty the paint. And you are putting on 150 mils of epoxy!!!!
HOLY F%^*
Reply With Quote Quick reply to this message
  #18 (permalink)  
Old 11-19-2004, 09:50 AM
Member
 
Last photo:
Join Date: Nov 2004
Location: Lakeland FL
Age: 65
Posts: 4,110
Wiki Edits: 0

Thanks: 0
Thanked 3 Times in 3 Posts
I must have been brain dead

To BarryK and sevt_chevelle,

I went back and deleted almost all of my last post, I have no idea why I kept writing 150 and 300 mils.

Barry,
My math was wrong (so I deleted it), but so is yours.

"300 mils to fill 36 grit, try 1.23 mils it will work better"?

1" of paper/36 grains per inch = .027" (27 mils) grain size

sevt_chevelle,
I deleted the 36 grit plastic filler tooth analogy.
You need to delete "take a 36 grit to some of them" from your post because it reads that you do use 36 grit for epoxy prep.
That's why I wrote "36 grit for epoxy, your kidding right?"
No you don't use 36 grit on a hood for anything, twice I wrote use 180 for bare steel epoxy prep on a hood.

your paper business card thickness equals all the paint layers thickness (10 mils) is correct, I measured about 10 different ones, all were very close to .010" thick.

Another way to visualize it is 3mil construction/drop cloth polyethylene sheeting, it's pretty accurate.

A 6 mil OEM finish is 2 layers of 3 mil poly, God that looks thin, amazing what those robots can do.

To help visualize .75mils plus of epoxy thickness, a kitchen trash can liner is .95mils thick. You need a magnifying glass to see the thickness.

Lets see, a stack of 30 (10mil) paper business cards is 300 mils of coating thickness, oh yeah, I'm OK, really I am, just ask my doctor.
Reply With Quote Quick reply to this message
  #19 (permalink)  
Old 11-19-2004, 10:08 AM
Member
 
Last photo:
Join Date: Apr 2004
Location: Georgia
Posts: 3,578
Wiki Edits: 0

Thanks: 10
Thanked 61 Times in 39 Posts
RE: Grit,
Sorry my math is on the money,
your forgetting the grit is covered with a resin.
Reply With Quote Quick reply to this message
  #20 (permalink)  
Old 11-19-2004, 10:52 AM
Member
 
Last photo:
Join Date: Nov 2004
Location: Lakeland FL
Age: 65
Posts: 4,110
Wiki Edits: 0

Thanks: 0
Thanked 3 Times in 3 Posts
More than 95% of the .027" ( 27 mil) 36 grit grain would have to be imbedded in the resin to get to a .0012" ( 1.2 mil) scratch depth.
Reply With Quote Quick reply to this message
  #21 (permalink)  
Old 11-19-2004, 11:02 AM
Member
 
Last photo:
Join Date: Apr 2004
Location: Georgia
Posts: 3,578
Wiki Edits: 0

Thanks: 10
Thanked 61 Times in 39 Posts
Figure it out, resin coated disc's grit are sunk in the resin unlike 6 inch DA paper.

Your talking 20,000 rpm vs 1000?
The percentage will also very by coarseness of grit such as 50 vs 16.

This don't make a hill of beans and is a waste of discussion but proves tech sheets tell you only what they want you to know and very few things in this business you can just make a blanket statement.
Reply With Quote Quick reply to this message
  #22 (permalink)  
Old 11-19-2004, 12:36 PM
Member
 
Last photo:
Join Date: Nov 2004
Location: Lakeland FL
Age: 65
Posts: 4,110
Wiki Edits: 0

Thanks: 0
Thanked 3 Times in 3 Posts
Barry, how deep of a scratch will this make

Measured the grit and paper thickness of a new Norton Red Resin 60 grit disk without the silicone backing. It measures .038" (38 mils) thick.

Filed the grit off to the resin. It measures .025" (25 mils) thick.

So the new 38 mil thick paper with grit minus the no grit left 25 mil paper = 13 mils of grit not imbedded in the resin right?

Hey, that means that 80% of the 60 grit .016" grit grain wasn't buried in the resin right?

How deep will new 60 grit paper cut with .013" (13mils) of exposed grit cut?
Reply With Quote Quick reply to this message
  #23 (permalink)  
Old 11-19-2004, 12:53 PM
Member
 
Last photo:
Join Date: Apr 2004
Location: Georgia
Posts: 3,578
Wiki Edits: 0

Thanks: 10
Thanked 61 Times in 39 Posts
Wait a minute! Every time you get called you edit your post or change story.
We were talking about 36 grit.
Also where did you find red Norton grinding dics the blue is their big seller, stronger more coating.
The main players are Green-3m
Blue-norton
Give it up this is useless and meaningless.
Reply With Quote Quick reply to this message
  #24 (permalink)  
Old 11-19-2004, 01:00 PM
Member
 
Last photo:
Join Date: Nov 2004
Location: Lakeland FL
Age: 65
Posts: 4,110
Wiki Edits: 0

Thanks: 0
Thanked 3 Times in 3 Posts
congratulations Barry

you got one thing right!

As the grit gets finer (ex: 36 grit and 80 grit), the grit is buried deeper in the resin, it does cut less deep grooves, the resin has to have more of the grit grain surface area to keep the grit on the paper,

pretty logical huh.

Sorry, rpms has very little to do with cut depth. It's the pressure applied while sanding that determines the cut depth
Reply With Quote Quick reply to this message
  #25 (permalink)  
Old 11-19-2004, 01:08 PM
Member
 
Last photo:
Join Date: Apr 2004
Location: Georgia
Posts: 3,578
Wiki Edits: 0

Thanks: 10
Thanked 61 Times in 39 Posts
Never said it did!
Rpms require more resin to stay together, thats why da paper uses glue and striate and grinding disc use resin.
Grit makes scratches.
Reply With Quote Quick reply to this message
  #26 (permalink)  
Old 11-19-2004, 01:40 PM
Member
 
Last photo:
Join Date: Nov 2004
Location: Lakeland FL
Age: 65
Posts: 4,110
Wiki Edits: 0

Thanks: 0
Thanked 3 Times in 3 Posts
gee Barry

I didn't know it has to be a blue Norton disk to calculate the cut depth.

So blue Norton 36 grit disks have 95% of the grit buried in the resin to make a 1.2 mil deep scratch right.
Reply With Quote Quick reply to this message
  #27 (permalink)  
Old 11-19-2004, 01:48 PM
Member
 
Last photo:
Join Date: Apr 2004
Location: Georgia
Posts: 3,578
Wiki Edits: 0

Thanks: 10
Thanked 61 Times in 39 Posts
Of course! I quit.
I just want to agree!
Reply With Quote Quick reply to this message
  #28 (permalink)  
Old 11-19-2004, 03:13 PM
Member
 
Last photo:
Join Date: Nov 2004
Location: Lakeland FL
Age: 65
Posts: 4,110
Wiki Edits: 0

Thanks: 0
Thanked 3 Times in 3 Posts
thank you Barry

for finally agreeing that your math was wrong for 36 grit scratch depth

my grit scratch math was wrong, I admitted it (and deleted it because NOTHING is worse than wrong information)


good luck to you
Reply With Quote Quick reply to this message
  #29 (permalink)  
Old 11-19-2004, 04:49 PM
Member
 
Last photo:
Join Date: Nov 2004
Location: Lakeland FL
Age: 65
Posts: 4,110
Wiki Edits: 0

Thanks: 0
Thanked 3 Times in 3 Posts
To sevt_chevelle, 36 grit for filler

I do know why the 36 grit came to mind for filler prep. I've got to use it (and probably a kiss with a grinder) to redo a repair that somebody did 3 years ago that didn't hold.

On early Mustang doors there is a very pronounced sharp scallop line on the top third of the door. It almost screams "hit me" in a parking lot.

On this door, a van door slammed into the scallop line and put almost a 3/8" deep crease in it (of course it's where you can't get to it from inside the door).

The repair failed because the door gets slammed shut/shocked the 80 grit (?) 1"x 1"x3/8" prepped plastic bond every day .

Plan "B" is a new $350 door shell plus assemble/fit/paint, because the inner bottoms are gone, so a skin is a waste.

Plan "C" cut it out and weld in a patch, good luck, it's a very convex and concave area and to get the line back straight ? And you can't get to the back to treat for rust, doors are always wet inside.

So 36 grit it, kiss it with a grinder (Mustang doors do have plenty of steel) and fill it.
I will try to reset the latch so the door jam bumpers cushion better if it will line up with the quarter.

Otherwise I use the grit that seems logical and best for the fill repair and the area I'm working on
Reply With Quote Quick reply to this message
  #30 (permalink)  
Old 11-21-2004, 08:41 PM
Member
 
Join Date: Jan 2004
Location: Overland park, Kansas burb of KC
Posts: 244
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
My daily driver Ford Ranger has a good portion of the drivers door in filler. Its lasted since I bought the truck back in 2000.

I bought it wrecked, door had damage. Pulled it out to level as possible, removed paint with my 8in mud hog da sander with 80 grit and applied filler.

When the EVERCOAT rep stopped by my shop where I worked we had a nice chat about fillers and the prep. He said 80 grit on bare metal is just fine.

I know what a early mustang looks like I helped a good friend of mine restore his 65 fastback. Sorry but I have a VERY hard time swallowing that 1x1x3/8 spot of filler failed because the guy used 80 grit instead of 36.

If whoever did this to a door with rotted bottoms probably didnt have a clue in the beginning.
Reply With Quote Quick reply to this message

Recent Body - Exterior posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -6. The time now is 09:14 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.