correct way to heat & quinch - 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
  #1 (permalink)  
Old 04-23-2013, 08:26 AM
Registered User
 

Last journal entry: Still running strong
Join Date: Dec 2011
Location: Lakehills Tx
Posts: 607
Wiki Edits: 0

Thanks: 52
Thanked 45 Times in 43 Posts
correct way to heat & quinch

I have a half moon shaped area on the roof of my 78 Camaro almost between the t-tops that is high. Its about 10 ins. long. I don't know if you could call it oil canned because it hard to press it back down,but I can put pressure on it with my thumb an it'll go back down. I can't get to it from the bottom. Question is how hot should I make it before quenching. Red hot, or until the metal starts to change color? I've done this with small low spots but all I did was heat them until the metal got kind of blueish an they pop out. I'm going to have to make this shrink not expand. The only other thing I can think of would be to drill holes in it then put so weight on it an tack it to the frame work.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 04-23-2013, 08:38 AM
Registered User
 
Last wiki edit: General Motors transmissions Last photo:
Join Date: Mar 2006
Location: near Yellowstone park
Posts: 4,463
Wiki Edits: 27

Thanks: 13
Thanked 284 Times in 264 Posts
body twist?

Before heating I would check to see if the body is distorting. T tops are weak and after time they can bend -twist. I used to jack up my convertible and have jack stands in the center and my brother would get on one end and i would get on the other and we would teeter totter and after a few times put the wheels back on the ground and the doors would fit and close right again for a while. My 5.0 Fox body Capri T top had all the typical Mustang problems. cracks in the floor, , qtr panels , rear suspension mounts. I bought a sub frame kit, added more reinforcement, and a roll bar, It really helped handling and I haven't seen any more new cracks.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 04-23-2013, 09:18 AM
put up or shut up
 

Last journal entry: saying goodbye to the beast
Last photo:
Join Date: Apr 2011
Location: Antelope, Ca
Posts: 2,194
Wiki Edits: 0

Thanks: 644
Thanked 266 Times in 242 Posts
that's a brow, or the wave created from a ding indirectly. Don't know for sure but maybe you should block in that area and look for the low spot. Once you find it you can use a stud welder and as you are lifting that area you can use a slapper and slap down the area, "rolling" out the damage. or it could be bracing shoving it upwards. hit lightly with a hammer. solid or hollow sounding?
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 04-23-2013, 10:21 AM
MARTINSR's Avatar
Brian Martin,Freelance adviser
 
Last photo:
Join Date: Jun 2004
Location: San francisco bay area
Age: 56
Posts: 13,432
Wiki Edits: 0

Thanks: 1,567
Thanked 1,320 Times in 1,146 Posts
Quote:
Originally Posted by timothale View Post
Before heating I would check to see if the body is distorting. T tops are weak and after time they can bend -twist. I used to jack up my convertible and have jack stands in the center and my brother would get on one end and i would get on the other and we would teeter totter and after a few times put the wheels back on the ground and the doors would fit and close right again for a while. My 5.0 Fox body Capri T top had all the typical Mustang problems. cracks in the floor, , qtr panels , rear suspension mounts. I bought a sub frame kit, added more reinforcement, and a roll bar, It really helped handling and I haven't seen any more new cracks.

X2! Those T top roofs get bent VERY easy when the car is rear ended, VERY easy. So you may want to look at the bigger picture and have the body checked and pulled to relieve the pressure that is causing that high spot. There will often be a buckle as well and you could repair it all without the pull but you may want to look into that as the body could be out of whack and you want to correct it. This damage isn't the same as on a regular roof where something has struck it and caused a dent and a brow. It could be don't get me wrong but the roof on these cars bend SO EASY when struck from behind it is VERY common for them to be distorted do to this.

Brian
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 04-23-2013, 06:27 PM
Registered User
 

Last journal entry: Still running strong
Join Date: Dec 2011
Location: Lakehills Tx
Posts: 607
Wiki Edits: 0

Thanks: 52
Thanked 45 Times in 43 Posts
Again my question is the proper way to shrink this brow, thanks it is a brow. I don't have a shrinking disc but have propane and ace torchs. Should I use ice water to quince? Im mostly concerned about heat level to bring it to. The head liner is out. Yes there was some minor rear end damage at one time but I cant do anything about that. Ive been trying to post pics but must not be holding my mouth the right way.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 04-24-2013, 06:23 AM
Old Fool's Avatar
Registered User
 
Last photo:
Join Date: Jan 2008
Location: spokane,wa.
Posts: 1,347
Wiki Edits: 0

Thanks: 8
Thanked 40 Times in 34 Posts
I suggest using a shrinking disc.

Go to fleabay and buy a shrinking disc and video by Wray Schelin

Shrinking Disc Combo English Wheel Planishing Hammer | eBay
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 04-24-2013, 06:24 AM
Old Fool's Avatar
Registered User
 
Last photo:
Join Date: Jan 2008
Location: spokane,wa.
Posts: 1,347
Wiki Edits: 0

Thanks: 8
Thanked 40 Times in 34 Posts
deleted, double post
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 04-24-2013, 08:25 AM
MARTINSR's Avatar
Brian Martin,Freelance adviser
 
Last photo:
Join Date: Jun 2004
Location: San francisco bay area
Age: 56
Posts: 13,432
Wiki Edits: 0

Thanks: 1,567
Thanked 1,320 Times in 1,146 Posts
Quote:
Originally Posted by Old Fool View Post
I suggest using a shrinking disc.

Go to fleabay and buy a shrinking disc and video by Wray Schelin

Shrinking Disc Combo English Wheel Planishing Hammer | eBay
X2


Brian
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 04-24-2013, 09:08 AM
put up or shut up
 

Last journal entry: saying goodbye to the beast
Last photo:
Join Date: Apr 2011
Location: Antelope, Ca
Posts: 2,194
Wiki Edits: 0

Thanks: 644
Thanked 266 Times in 242 Posts
be sure to block on it first as shrinking is done last after metal work.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 04-24-2013, 09:11 AM
MARTINSR's Avatar
Brian Martin,Freelance adviser
 
Last photo:
Join Date: Jun 2004
Location: San francisco bay area
Age: 56
Posts: 13,432
Wiki Edits: 0

Thanks: 1,567
Thanked 1,320 Times in 1,146 Posts
If you really wanted to try to shrink it with a propane torch I have to tell you I believe you are going to end up with a mess. I have tried it and it is very difficult to control. Basically you would try to heat the smallest area you could and then quinch it with with a water soaked rag or even blowing air from a compressor right down close on the metal can do it. But the water is the best bet. The problem with those little torches is they aren't hot enough and to get it hot enough you have to hold it there quite a while and you are heating the surrounding area way too much. Not hot enough to really shrink it, but hot enough to warp it all to hell.

When you shrink with a torch it is a very controlled shrink, you get down in there with an acy torch and you heat a dime sized area VERY quickly. You then have that dime sized area that is soft and molecules dancing around, you lightly strike it "off dolly" with the dolly not pressed hard against the metal on the underside, "pushing" that metal together cramming the molecules closer together. Or doing the same thing with a water soaked rag "shocking" the molecules that are dancing around in the warmed metal making them gather. This also hardens the metal, not usually a big deal but it can get overworked.

The other thought is to strike the metal around the heated dime with a "pushing" motion towards the center of the heated "dime" gathering up the metal there on a microscopic level.

You can see how this just isn't possible with a propane torch, you will likely warp that area horribly if you try this with that propane torch.

The "shrinking disc" is a VERY interesting tool. Think of it as a "heat block" where you are only heating the high spots, ONLY the high spots right? The disc is running over the top of the metal and you are only heating the high spots. You quench them with a wet rag or air and you are ONLY shrinking the high spots, very cool.

But honestly, if your roof is doing that because of the car being hit in the back and now there is too much metal in that spot because the structure got "shortened" there. This can be WAY too much metal, shrinking it down could be very difficult. Or it isn't that big of a deal, without seeing it first hand it's hard to say.

If it is a "brow" like you usually see next to a dent, well then that is a different story and you need to not so much push that brow down but to raise up the low area next to it. The high AND the low are working as a team and you need to do both. Is it a SHARP "brow"?

I couldn't find any real good photos but this is an extreme example of what I am talking about. The upper part of this dent is the "brow".



You see how it would be "holding" that low spot down. But at the same time if you are applying pressure to the back side of that low spot when tapping on the brow it all wants to even out, with the high coming down and the low going up. (or out in this case).

Often the low in a "gentle" dent like on a roof panel isn't as pronounced as this. It is often hard to see the low spot, you see only the brow. It is possible your damaged area is caused by something striking it like a fist, or a baseball or something where it doesn't show an clear "impact" area like this one in the photo does. It is VERY common on a roof to have these type of dents round the edges when the whole roof has been caved in! Someone walks on the roof and then it gets "popped" back up and you end up with brows around the perimeter of the panel. But next to each and every one of these brows is a low spot, just like in this photo I have posted.

Look over your dent very closely to see if there is this low spot, that would be a very good thing because it means your metal may not need shrinking at all, or a lot less. Often that low spot is pushed up and the brow tapped down and WHAM you are done.

Look at it closely and give it a LOT of respect, a 10 inch long area to shrink is asking a LOT for someone who isn't well versed in this stuff.

Brian
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 04-24-2013, 09:16 AM
MARTINSR's Avatar
Brian Martin,Freelance adviser
 
Last photo:
Join Date: Jun 2004
Location: San francisco bay area
Age: 56
Posts: 13,432
Wiki Edits: 0

Thanks: 1,567
Thanked 1,320 Times in 1,146 Posts
This is a better photo showing the brows, the white areas where the panel has been sanded, you can clearly see that there is a brow, and a low spot next to each brow where the paint didn't get sanded.

Brian

Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 04-24-2013, 09:23 AM
MARTINSR's Avatar
Brian Martin,Freelance adviser
 
Last photo:
Join Date: Jun 2004
Location: San francisco bay area
Age: 56
Posts: 13,432
Wiki Edits: 0

Thanks: 1,567
Thanked 1,320 Times in 1,146 Posts
Here is another good one, with a sun roof. This dent could be caused by someone pushing down on the sun roof "hole" or from a hit in the back or front. It is VERY common to see the corners of the sun roof to be damaged like this with a hit to the front or rear of the car.

Brian

Reply With Quote Quick reply to this message
The Following User Says Thank You to MARTINSR For This Useful Post:
dogwater (04-25-2013)
  #13 (permalink)  
Old 04-25-2013, 07:51 AM
Registered User
 

Last journal entry: Still running strong
Join Date: Dec 2011
Location: Lakehills Tx
Posts: 607
Wiki Edits: 0

Thanks: 52
Thanked 45 Times in 43 Posts
Its like photo no.3. Its like a crescent moon shape. My long board only sanded off an in. wide to bear metal but when I run my hand over it its much wider. This wouldn't be such a problem if I could get to the bottom of it, theirs framing on the under side that covers the bottom of the brow. As far as height its about the thickness as a quarter. Just a quick question, when sheet metal is heated an left to air cool does it shrink any? I know it expands. And when heated sheet metal is quenched is it the quenching that shrinks the metal? The shrinking disc as you described is most likely what I need to do. Thanks Brian you've been very helpful.
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 04-25-2013, 08:52 AM
MARTINSR's Avatar
Brian Martin,Freelance adviser
 
Last photo:
Join Date: Jun 2004
Location: San francisco bay area
Age: 56
Posts: 13,432
Wiki Edits: 0

Thanks: 1,567
Thanked 1,320 Times in 1,146 Posts
When you heat it and don't cool it, it doesn't shrink and in fact may stay expanded a little because. Quenching it is one way to shrink it, as I described when you lightly strike it with the hammer in an "off dolly" method the molecules of the metal are being pushed together. So no, you don't have to quench at all to shrink. Quenching is actually "cheating" when it comes to shrinking. The quenching is a quick way to gather the molecules in the metal pulling them tighter together.

Picture this, when you heat metal with a torch you could keep heating until it melts right? What is happening is the molecules in the metal start to move around. They are in this perfect little pattern when you start, like the weaves in a cloth. You heat them up and they start moving around, when you keep heating, the keep moving more and more and more until they fall apart, the metal is melting and becoming a "liquid" for a bit before it cools and becomes a solid again. When you heat it up enough for the molecules to be dancing around and then you quench it, the gather tighter with the shock of the cooling, thus gathering the metal tighter. And again, it's also making the metal harder so you can over do this making the metal brittle.

But if you really have something like photo 3 it is likely very little shrinking if any is needed. You need to push up the or pull it up with a stud gun while gently tapping down the brow. And you can shrink with that stud gun too. They have tips to shrink with it. I don't like it because the tip is spring loaded and pushing really hard on the metal as it heats it so you get a good little dent, but as a last resort it can do the trick.

Brian
Reply With Quote Quick reply to this message
The Following User Says Thank You to MARTINSR For This Useful Post:
dogwater (04-26-2013)
  #15 (permalink)  
Old 04-25-2013, 09:34 AM
put up or shut up
 

Last journal entry: saying goodbye to the beast
Last photo:
Join Date: Apr 2011
Location: Antelope, Ca
Posts: 2,194
Wiki Edits: 0

Thanks: 644
Thanked 266 Times in 242 Posts
shrinking tips are great when you're working on classic cars and not tin cans.i have never had an issue with the spring causing a ding. if it becomes too low it's because the heat was localized and not spread around. a 1978 car is not a tin can.


If you don't have a stud gun to pull up the lows just use a spoon under a hammer and hammer the brow down and fill. Shrinking is always last resort and you try to avoid it when possible. The biggest problem I see with shrinking is guys will have an oil can and instantly think "shrink-shrink-shrink" but if they spend the time to analyze what's around the stretch and work it out chances are high that the area will tighten back up by itself.
Reply With Quote Quick reply to this message
The Following User Says Thank You to tech69 For This Useful Post:
dogwater (04-26-2013)

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:
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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Correct size & type of radiator fan & clutch? Steve S Engine 3 12-04-2006 11:29 AM
Heat & Air setup 37fordpickup Electrical 3 11-14-2006 05:47 PM
Correct Alt Amp gazrnr Electrical 2 09-18-2005 09:45 PM
Heat, Cold & Moisture rick1956 Garage - Tools 2 11-13-2004 02:55 PM
understanding quinch Jmark Engine 4 09-06-2003 04:40 PM


All times are GMT -6. The time now is 04:08 PM.


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.