Glass Transition Temperatures

[Aaron]

I'm looking for manufacturer published glass transition temperatures for available epoxies, anyone know of a convenient link?

 

I'm most interested in something with a glass transition temp higher than 250 derees F- I thought I'd play with making a custom intake to replace the aluminum monstrosity sitting on my bench. Any suggestions?

[John Slade]

Talk to Bruce Turrentine,

See: http://www.rotaryaviation.com/custom_mazda_engines.html

Bruce is making an intake system for the Mazda using high temp epoxy.

He's at Sun & Fun right now.

[Aaron]

Derakane 470-300 data:

 

http://www.dow.com/webapps/lit/litorder.asp?filepath=derakane/pdfs/noreg/125-00271.pdf&pdf=true

 

There is a higher temp version available, but 300 degrees should give me room to spare for an intake.

 

Apparently, more important than the glass transition temp is the heat distortion temp, for this material it's 300F when properly cured.

 

Next steps in the process:

2) Locate a gallon supplier of Derakane 470-300 and appropriate catalyst

 

3) Create and test tubes

[CBarber]

Following....letting you be the guinie pig. Keep us posted. Will be interested in Bruce T's progress as well.

[marbleturtle]

... yes please let us know the results of your testing. Intake plumbing seems to be the biggest obstacle for automotive conversions.

[Aaron]

ACP (Aerospace Composite Products) e-mail: info@acp-composites.com

 

has a resin they call EZ-LAM HT:

E-Z LAM HT

High Temperature

Epoxy Laminating Resin

 

 

 

DESCRIPTION:

An ultra high temperature laminating system for the construction of laminated composite parts. E-Z LAM HT has excellent wet-out characteristics, facilitating lay-ups involving compound contours. Its long pot life allows for ease of vacuum bagging . The maximum operating temperature for laminated parts manufactured from E-Z LAM HT is 450 Deg. F.

 

MIX RATIO: 100 parts by weight E-Z LAM HT A

33 parts by weight E-Z LAM HT B

 

POT LIFE: 150 gr. mass 4 HRS. @ 75 F

 

CURE: ROOM TEMP SET

FOLLOWED BY

2 HRS. @ 150 F

2 HRS. @ 200 F

2 HRS. @ 250 F

2 HRS. @ 300 F

2 HRS. @ 350 F

ALLOW TO COOL IN OVEN

 

PROPERTIES: VISCOSITY, MIXED 5000 CPS

DUROMETER D 94 SHORE

SPECIFIC GRAVITY 1.19 gm/cc

USE TEMP, 400 F

FLEXURAL 102,000 PSI

COMPRESSION 64,000 PSI

TENSILE 57,000 PSI

 

SHELF LIFE: Twelve months when stored in tightly sealed containers at room temperature.

 

SAFETY:

Avoid contact of resin or hardener with skin or eyes. Wear disposable gloves and eye protection. Avoid breathing vapors, apply under good ventilation. If contact occurs consult physician. For more details refer to E-Z LAM Safety Sheet.

[dust]

Arron, this is great info and I'm sure to use it, tanks

[Aaron]

Hey dust, what do you need the High-temp stuff for?

[dust]

Well, on the turboe i have a convective and a conductive heat problem. need to retain heat to the turboe and disapate it from there on out. I don't know what i will need to fabricate, but knowing about the appropiate materials will give me options. Looking forward with happines and dred

[Aaron]

I think you mean you need to shield the exhaust half of the turbo and the manifold from everything else. I've seen this done using insulated pads which tie on around the exhaust piping, they're made to withstand 2000F heat. I did see one lancair where the builder used a carbon composite material outside the silica fabric, but I'm not sure it ever flew:

 

http://www.hannestrnka.com/heat_shield.htm

 

It shore is purdy though :0 look at his CF ducts:

 

http://www.hannestrnka.com/cooling_air_ducts.htm

[Aaron]

http://www.scudc.scu.edu/spec/mcad/analysis/MIL-HDBK-17-2E.pdf

 

451 pages of composite materials tests.

[Aaron]

AS&S sells "Promoted Derakane" basically it's resin premixed with promoters, the only thing you have to add is catalyst. How much catalyst is hard to find out.

 

I started with 80g of Derakane 411-350PA, and added 2grams of catalyst, to make a tiny flat layup for testing. resin was originally at 85F

 

Note: all temp readings done with an infared noncontact thermometer.

 

My garage was around 90F, humidity was about normal for Houston.

 

My first impression was "wow, this stuff wets out SO much easier than aeropoxy"

 

My next was "Hmmn, the cup temperature is 110F.. I should hurry up."

 

30 seconds later the cup was at 140F and had solidified. Total working time was about 10-15 minutes. A few minutes later the cup reached 270F, and eventually it peaked at 280F.

 

Lesson learned-it takes VERY little catalyst to work with Derakane PA.

 

Tonight I'm going to test at 1g catalyst /100g resin too see what kind of working time I can get.

 

My eventual goal is to have several test strips made of 6 layers of BID. I'll post cure them to different degrees to see which ones can retain shape under a fixed load at 300F.

 

This would make a great science fair project for anyone with high school kids...

[LargePrime]

dust;

You might try ceramic coatings on your exhaust manifold and turbo housing. fellows tell me they keep the heat in the turbo and exhaust. Wraps are good too, but a caution. they retain moisture and have been known to rust out parts. If used with a ceramic coating then you got less rust worry. They also have a tendancy to fall off eventualy. I would guess thats bad for the prop. But i only seen/heard about atuomotive use. perhaps there are aircraft ones that are tuffer, or make it an inspection issue.