BMW M3 Forum
BMW M3 Forum BMW M3 Gallery BMW M3 Reviews BMW M3 Social Groups BMW M3 Chat M3Forum Sponsors >>
Loading


Mobile M3forum
Go Back   BMW M3 Forum.com (E30 M3 | E36 M3 | E46 M3 | E92 M3 | F80/X) > M3Forum Garage > Faults, Fixes and DIY
Tire Rack Buy Winter Tires Now!
Not a member? Register Now!
Register Gallery All Albums Garage Search Today's Posts Mark Forums Read Calendar FAQ

Faults, Fixes and DIY Please share your experience and knowledge with other members by contributing your own DIY, or by helping another member find the elusive fix!


Reply
 
Thread Tools Display Modes
Old Fri, Feb-26-2010, 12:49:12 AM   #21
ospfbgp
Registered User
 
Join Date: Sep 2004
Age: 45
Posts: 158
Reputation: 0 ospfbgp is on a distinguished road
Location: Georgetown, KY

United States




Default

WOW that was an awesome job. Very interesting.

I wonder if you just did the epoxy with the turner kit would that be enough to sure up the frame so you would not have a failure, assuming you did not already have any damage. Just to help reinforcement. I am not an expert but if someone would inject there opinion that would be great. I think epoxy with the turner kit would not be a bad diy. I could always do the work and then get a mobile welder to come and do the work .

Opinions?
Jump to top ospfbgp is offline   Reply With Quote
Sponsored Links
Register now and remove these ads
Old Thu, Mar-11-2010, 05:25:27 AM   #22
DigitalPunk
Registered User
 
Join Date: Feb 2010
Posts: 131
Reputation: 0 DigitalPunk is on a distinguished road

United States




Default

I think this is the Cavity foam

http://cgi.ebay.com/ebaymotors/LORD-...motiveQ5fTools

There is also an auction that comes with the gun.

And the structural foam is already linked a couple posts back.

http://outboundlink.net/out.php?cid=...849%26page%3D2

Above is what I ordered anyways and I am pretty sure its what BMW is using, but I could be wrong. can any one chime in?

Last edited by DigitalPunk; Thu, Mar-11-2010 at 05:32:23 AM.
Jump to top DigitalPunk is offline   Reply With Quote
Old Fri, Mar-12-2010, 07:27:54 PM   #23
DigitalPunk
Registered User
 
Join Date: Feb 2010
Posts: 131
Reputation: 0 DigitalPunk is on a distinguished road

United States




Default

Quote:
Originally Posted by DigitalPunk View Post
I think this is the Cavity foam

http://cgi.ebay.com/ebaymotors/LORD-...motiveQ5fTools

There is also an auction that comes with the gun.

And the structural foam is already linked a couple posts back.

http://outboundlink.net/out.php?cid=...849%26page%3D2

Above is what I ordered anyways and I am pretty sure its what BMW is using, but I could be wrong. can any one chime in?
Any one ?
Jump to top DigitalPunk is offline   Reply With Quote
Old Wed, Mar-17-2010, 12:19:10 PM   #24
DigitalPunk
Registered User
 
Join Date: Feb 2010
Posts: 131
Reputation: 0 DigitalPunk is on a distinguished road

United States




Default

I found some instructions for this in a PDF file. And in these instructions it is the lord fusor 1908 that is being used.

I attached the PDF with the instructions. These are a little different then the other instructions as they want you to shoot seam sealer in before using the foam.

Going to need 8 bottles of it total if you want to do both sides. Looks like BMW just does one side though.

Hope it helps
Attached Files
File Type: pdf EpoxyFloorRepair-Fusor1908.pdf (410.6 KB, 247 views)
Jump to top DigitalPunk is offline   Reply With Quote
Old Mon, Mar-22-2010, 08:19:21 PM   #25
smilner
Registered User
 
Join Date: Mar 2010
Posts: 5
Reputation: 0 smilner is on a distinguished road

United States




Default

I take it that you don't just use any sort of bolt and to use the ones that are more able to take the stress load. I can see where the epoxy will help alot, but if the bolt shears off, then it's likely to crack even more.

Not a bad idea to find a mobile welder to add that extra protection.

Good DIY tho'.
Jump to top smilner is offline   Reply With Quote
Old Thu, Mar-25-2010, 02:05:28 AM   #26
Function7
Registered User
 
Function7's Avatar
 
Join Date: May 2009
Posts: 530
Reputation: 0 Function7 is on a distinguished road
Location: Mesa AZ

United States




Default

Speaking from my experience in aerospace composite manufacturing, I felt that I should correct this error/misconception before someone else makes the same mistake when they install their reinforcement plates. (more below)

Quote:
Originally Posted by Jeppe View Post
Mount the plates and lightly tighten the bolts. Don't tighten to hard cause you will squeeze out all the epoxy. I think the epoxy needs a layer of 0.5mm-1mm thick layer of epoxy to get max strenght. You should see some epoxy squeezing out evenly around the edge of the plate. Make sure you don't block the small drainage holes with epoxy.
Almost all (of not all) are designed to work best with a thinnest bondline (thinnest layer) as possibe. I looked up the datasheet for 3M 8115 and found the following:

Adhesion to Steel at Varying Bondline Thickness

*all adhesion values in psi
Bondline Thickness 0.036" thick steel 0.057" thick steel
10 mils 2690 3935
20 mils 2638 3863
32 mils 2653 3693
41 mils 2601 3510
47 mils 2432 3268


You'll notice that thicker bondlines result in poorer adhesion. Jeppe mentions using a 0.5-1mm thick layer (that's 20-40 mils) while typical adhesives are designed for a 5-12 mil bond line. For 3M 8115, the recommended thickness is 10-12 mil. To make sure this is correct 3M 8115 even goes one step further - there are small glass beads mixed into it that ensures proper bondline thickness.

Going thicker than the design specs also results in different curing characteristics and this may result in internal stresses within the thick epoxy layer that eventually reduces the strength.

Anyway, if you choose to use epoxy to attach the reinforcement plates (yes, modern epoxies can be stronger than welds - seen it first hand) remember to squeeze out as much of the epoxy from between the two bonded surfaces as possible. Clamp it down, apply pressure, and let it sit and cure.

Still haven't found cracks on my car but if it does become an issue, this will be my preferred repair methodology, however I'd probably look at different epoxies too.

-A

Last edited by Function7; Thu, Mar-25-2010 at 05:45:57 AM.
Jump to top Function7 is offline   Reply With Quote
Old Thu, Mar-25-2010, 08:09:24 AM   #27
DigitalPunk
Registered User
 
Join Date: Feb 2010
Posts: 131
Reputation: 0 DigitalPunk is on a distinguished road

United States




Default

Quote:
Originally Posted by Function7 View Post
Speaking from my experience in aerospace composite manufacturing, I felt that I should correct this error/misconception before someone else makes the same mistake when they install their reinforcement plates. (more below)



Almost all (of not all) are designed to work best with a thinnest bondline (thinnest layer) as possibe. I looked up the datasheet for 3M 8115 and found the following:

Adhesion to Steel at Varying Bondline Thickness

*all adhesion values in psi
Bondline Thickness 0.036" thick steel 0.057" thick steel
10 mils 2690 3935
20 mils 2638 3863
32 mils 2653 3693
41 mils 2601 3510
47 mils 2432 3268


You'll notice that thicker bondlines result in poorer adhesion. Jeppe mentions using a 0.5-1mm thick layer (that's 20-40 mils) while typical adhesives are designed for a 5-12 mil bond line. For 3M 8115, the recommended thickness is 10-12 mil. To make sure this is correct 3M 8115 even goes one step further - there are small glass beads mixed into it that ensures proper bondline thickness.

Going thicker than the design specs also results in different curing characteristics and this may result in internal stresses within the thick epoxy layer that eventually reduces the strength.

Anyway, if you choose to use epoxy to attach the reinforcement plates (yes, modern epoxies can be stronger than welds - seen it first hand) remember to squeeze out as much of the epoxy from between the two bonded surfaces as possible. Clamp it down, apply pressure, and let it sit and cure.

Still haven't found cracks on my car but if it does become an issue, this will be my preferred repair methodology, however I'd probably look at different epoxies too.

-A
Its not he question of the strength of the epoxy its the bonding strength to the steel. Welding melts the mettle together making it one, epoxy glues/bonds them together leaving 2 separate pieces.

Do you feel epoxy bonds steel together as well as welding them together?
Jump to top DigitalPunk is offline   Reply With Quote
Old Thu, Mar-25-2010, 10:57:24 AM   #28
DigitalPunk
Registered User
 
Join Date: Feb 2010
Posts: 131
Reputation: 0 DigitalPunk is on a distinguished road

United States




Default

Quote:
Originally Posted by Function7 View Post
Speaking from my experience in aerospace composite manufacturing, I felt that I should correct this error/misconception before someone else makes the same mistake when they install their reinforcement plates. (more below)



Almost all (of not all) are designed to work best with a thinnest bondline (thinnest layer) as possibe. I looked up the datasheet for 3M 8115 and found the following:

Adhesion to Steel at Varying Bondline Thickness

*all adhesion values in psi
Bondline Thickness 0.036" thick steel 0.057" thick steel
10 mils 2690 3935
20 mils 2638 3863
32 mils 2653 3693
41 mils 2601 3510
47 mils 2432 3268


You'll notice that thicker bondlines result in poorer adhesion. Jeppe mentions using a 0.5-1mm thick layer (that's 20-40 mils) while typical adhesives are designed for a 5-12 mil bond line. For 3M 8115, the recommended thickness is 10-12 mil. To make sure this is correct 3M 8115 even goes one step further - there are small glass beads mixed into it that ensures proper bondline thickness.

Going thicker than the design specs also results in different curing characteristics and this may result in internal stresses within the thick epoxy layer that eventually reduces the strength.

Anyway, if you choose to use epoxy to attach the reinforcement plates (yes, modern epoxies can be stronger than welds - seen it first hand) remember to squeeze out as much of the epoxy from between the two bonded surfaces as possible. Clamp it down, apply pressure, and let it sit and cure.

Still haven't found cracks on my car but if it does become an issue, this will be my preferred repair methodology, however I'd probably look at different epoxies too.

-A
Also, how do you feel about using epoxy to fix already cracked sub frames? With welding you fill the cracks, then grind them down and it looks as if there was never even a crack and is flush as the pieces are melted and fused back together, where epoxy would just be coating the crack and not welding them into one piece. This would concern me a bit.

Whats your feelings on this?

One reason I ask is a lot of you will start do the reinforcement kit and realize after you drop the sub frame that you do have cracks all over, specially under the bushings where you couldn't see them (Like I did).
Jump to top DigitalPunk is offline   Reply With Quote
Old Thu, Mar-25-2010, 12:21:40 PM   #29
0-60Motorsports
Established 1998....
 
0-60Motorsports's Avatar
 
Join Date: Mar 2004
Posts: 14,723
In the garage:
Reputation: 0 0-60Motorsports is on a distinguished road
Location: Al Manama, Bahrain

Bahrain




Default

WELD the cracks, then epoxy or weld the reinforcement kit. I'llbe going the welding way cos the guy who does welding for me does FIA cages etc and the welding way will be much faster for him! He has done a subframe repair and he did an amazing job on it!
__________________
EURO 04 M3 Mods: GC DA's / Eibach Sways / PF RTABs / RE RCAs / INTRAVEE II / ///MFEST Badges / M5 SMG Knob / VCSL: Bumper + Race Lip, CF Trunk, CF Diffusor / DIETZ TV in Motion / SuperSprint: Stepped Headers, Cat Deletes, Res X-pipe, Sport Muffler / Z8 Starter Button / Lamin-X / STM Paddles / OEM CSL: Steering, Interior, Intake, CF Roof / Terra MSS54HP CSL Clone + TTFS Tune / BBS CH's, LIGHTWERKZ / ST40's / DINAN RSB / RE Race Brace / BW Oil Cooler / 3.91 gears / Radium OCC
Jump to top 0-60Motorsports is online now   Reply With Quote
Old Thu, Mar-25-2010, 12:30:09 PM   #30
DigitalPunk
Registered User
 
Join Date: Feb 2010
Posts: 131
Reputation: 0 DigitalPunk is on a distinguished road

United States




Default

Quote:
Originally Posted by 0-60Motorsports View Post
WELD the cracks, then epoxy or weld the reinforcement kit. I'llbe going the welding way cos the guy who does welding for me does FIA cages etc and the welding way will be much faster for him! He has done a subframe repair and he did an amazing job on it!
I wouldn't do it any other way. Just curious about thus epoxy stuff. I welded my kit in myself and grinned down the welds in the cracks and on the plates ,you now coudent even tell there was cracks or reinforcement places on there cause they are now one with the car. I just don't see how epoxy can be better then welding. I mean, our cars (And almost every other car in the world) are held together by welds and not epoxy. Yes, the rust proofing on the inside of the subframe is burnt to a crisp but that's why you fill it with seam sealer or structural foam after your done.

Just hire a welder for an hour, wont cost ya more then a couple hundred bucks and you know it will work. Do not glue your car together for Christ sakes! How many cars have glued together frames? Or glued together roll cages? None I hope! just my opinion. I know some epoxies are used in automotive manufacturing to hold outer skins on cars but not on anything structural.

Last edited by DigitalPunk; Thu, Mar-25-2010 at 12:35:40 PM.
Jump to top DigitalPunk is offline   Reply With Quote
Reply

Bookmarks

Tags
diy, e46, epoxy or foam, method, reinforcement, subframe

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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

Forum Jump



All times are GMT. The time now is 03:58:58 PM.


Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
M3Forum.com and M3forum.net is in no way sponsored, endorsed or affiliated by or with BMW NA / BMW AG or any of it's subsidiaries or vendors.
BMW and M3 (E90 M3 | E92 M3 | E93 M3 | E46 M3 | E36 M3 | E30 M3) are registered trademarks of BMW AG.
M3Forum Terms of Service
Copyright 1999-2017 M3Forum.com
Discussing DIY: Subframe reinforcement epoxy/foam method. e46 in the Faults, Fixes and DIY Forum - Please share your experience and knowledge with other members by contributing your own DIY, or by helping another member find the elusive fix! at BMW M3 Forum.com (E30 M3 | E36 M3 | E46 M3 | E92 M3 | F80/X)