Sciencemadness Discussion Board

Fiberglass Cloth - Available in the US

subsecret - 10-8-2014 at 10:53

Just to bring this to the attention of anybody who is interested, I discovered some fiberglass repair cloth at my local Lowe's hardware store, and also at another one, halfway across the country. I immediately bought a package, and upon opening it, discovered that it was about half a square meter of very clean cloth. I encourage you to look for it in your local hardware stores, as it's better than aluminum foil for insulation.

Just wanted to bring this to your attention.

bondo-fiberglass-cloth-8-square-feet-20128.jpg - 64kB

mnick12 - 10-8-2014 at 10:55

Thanks! That is good to know.

Is it contaminated in any way with plastics or resins? Or is it pure fiber glass?

WGTR - 10-8-2014 at 11:36

Professional boating stores also sell it, since there is a lot of fiberglass in the boating world. I know I've seen it at West Marine.

forgottenpassword - 10-8-2014 at 11:43

You get them practically anywhere that sells polish and waxes and things to rub onto your car - they'll have fibreglass and fibreglass repair kits and the like.

It's handy as a fire blanket too. Once I had a pan of very hot Vaseline set on fire. Luckily I'd had my industrial fire safety training, and calmly and profesionally wrapped the sheet over the pan. Good thing to have around. I don't know what I would have done otherwise.

careysub - 10-8-2014 at 11:55

Quote: Originally posted by mnick12  
Thanks! That is good to know.

Is it contaminated in any way with plastics or resins? Or is it pure fiber glass?


It is pure glass cloth.

If it weren't it would be useless to the people who use it to make composites since a wide variety of different resins are in use (polyester, vinyl ester, epoxy).

Non-woven glass mat is coated with a binder and can only be used with polyester resin as a result.

Magpie - 10-8-2014 at 11:57

I have bought the Bondo fiberglass at an auto parts store.

Member ordenblitz told how to make nice flask insulation blankets using RTV silicone to keep the edges from fraying.

http://www.sciencemadness.org/talk/viewthread.php?tid=6528#p...

fiberglass blanket.jpg - 78kB

subsecret - 10-8-2014 at 18:06

Very nice! I actually have a "Thermowell" heating mantle, the kind with the ceramic interior and steel case, and I cut a square of glass cloth to line it to pad the flask.

Manifest - 10-8-2014 at 18:28

Haha I can find this stuff in my attic.



[Edited on 11-8-2014 by Manifest]

subsecret - 10-8-2014 at 18:32

Actually, fiberglass that is used in buildings is sprayed with a pigment and a polymer resin. IIRC, the insulation batts are then sent through an oven to activate the resin, so that the batt is stuck together. Also, it's not woven into a fabric, so it's difficult to make it into thin sheets. I used to use this household insulation, but I discovered that the impurities would char after being heated with an open flame.

[Edited on 11-8-2014 by Awesomeness]

Manifest - 10-8-2014 at 18:55

Oh, I'll try burning it tomorrow.
Did you try building your own well?

subsecret - 10-8-2014 at 21:45

Don't burn your house down ;)

I did try drilling my own well, but I hit a rock about 3 meters down. U2U me if you want to hear the whole story. We can make a section in whimsy for homemade wells. :D

Bert - 6-4-2015 at 22:35

After wrapping a 4000 ml beaker used in an improvised sand bath to dehydrate NAPA sourced battery electrolyte to concentrated sulfuric acid long ago, I can verify that the un faced building insulation grade of fiberglass batting I tried to use had other substances in it that charred- No fires or other issues prevented finishing the operation, but it didn't smell very good! (Considering the OTHER vapors coming off that beaker, this was the least of my concerns).

Loptr - 7-4-2015 at 04:54

After having sourced some woven fiber glass cloth I see it everywhere now. I also have purchased some red high-temp RTV silicone, so should be constructing a few blankets soon, hopefully.

I do have one question for you guys. How would the RTV silicone fair with being added to a solvent to liquify it temporarily? I was thinking of taking a tray the width of intended size of one side of the blanket, and then dip it a few times.

Would this work or will this have some negative effect on the RTV? From my minimal understanding of the RTV silicone, it doesn't require high temperatures to cure, room temperature vulcanizing, and I am not sure if the solvent would be detrimental or not.

careysub - 7-4-2015 at 06:24

Being able to buy locally is convenient, but you can also easily order it.

Aircraft Spruce (local for me) ships a variety of fiberglass fabrics everywhere. Particularly useful I think is fiberglass tape, it is selvage edged and so does not fray and which can be wrapped around most anything.

http://www.aircraftspruce.com/categories/building_materials/...

Soller Composites has fiberglass sleeving which may be useful as well:
http://www.sollercomposites.com/composites/carbon%20fiber%20...

They have in the past also had basalt sleeves which are also very high temperature, but do not currently seem to have any stocked.

careysub - 7-4-2015 at 06:41

Quote: Originally posted by Loptr  
After having sourced some woven fiber glass cloth I see it everywhere now. I also have purchased some red high-temp RTV silicone, so should be constructing a few blankets soon, hopefully.

I do have one question for you guys. How would the RTV silicone fair with being added to a solvent to liquify it temporarily? I was thinking of taking a tray the width of intended size of one side of the blanket, and then dip it a few times.

Would this work or will this have some negative effect on the RTV? From my minimal understanding of the RTV silicone, it doesn't require high temperatures to cure, room temperature vulcanizing, and I am not sure if the solvent would be detrimental or not.


If the solvent does not evaporate before the silicone sets, it is likely detrimental. A very low BP solvent that disappears before vulcanization is complete is probably okay. But you will need to test to confirm.

Low viscosity silicone RTVs exist, but they are specialty products and difficult to source for the individual.

Also consider silicone casting compound:
http://www.mcmaster.com/#=wnde71

It is a putty that can be formed by hand, and it good to 600F (higher than most gasket RTVs). Using this with fiberglass and a heating element might might make good heating mantles.

Magpie - 7-4-2015 at 08:39

Quote: Originally posted by Loptr  

I do have one question for you guys. How would the RTV silicone fair with being added to a solvent to liquify it temporarily? I was thinking of taking a tray the width of intended size of one side of the blanket, and then dip it a few times.


I think you are overthinking this. If you are intending to make a blanket like ordenblitz and I have made it is extremely simple:

1. Cut the blanket to size and lay it out on a piece of wax paper on a flat surface like your kitchen table.

2. Take the RTV and run a generous bead along the perimeter of the blanket.

3. Using a table knife or spatula spread the bead flat in a band about 1" wide, spreading it right up to the edge of the blanket. As you spread it this way it will soak through to the other side somewhat, which is good.

4. Let it cure overnight at room temperature.

5. Take a pair of scissors and cut down through the middle of the RTV band. Discard the trimming. Done. ;)

[Edited on 7-4-2015 by Magpie]

Loptr - 7-4-2015 at 08:51

Quote: Originally posted by Magpie  


I think you are overthinking this. If you are intending to make a blanket like ordenblitz and I have made it is extremely simple:

1. Cut the blanket to size and lay it out on a piece of wax paper on a flat surface like your kitchen table.

2. Take the RTV and run a generous bead along the perimeter of the blanket.

3. Using a table knife or spatula spread the bead flat in a band about 1" wide, spreading it right up to the edge of the blanket. As you spread it this way it will soak through to the other side somewhat, which is good.

4. Let it cure overnight at room temperature.

5. Take a pair of scissors and cut down through the middle of the RTV band. Discard the trimming. Done. ;)

[Edited on 7-4-2015 by Magpie]


Overthinking... my hallmark.

I had read the silicone doesn't make it through the blanket very well, and you had to turn it over and apply to the other side.

(or at least that is what I recall from ordenblitz's comments :-)

subsecret - 7-4-2015 at 10:50

Quote: Originally posted by Loptr  


I had read the silicone doesn't make it through the blanket very well, and you had to turn it over and apply to the other side.

(or at least that is what I recall from ordenblitz's comments :-)


I had to apply the silicone to both sides of the cloth, and it formed a pretty thick layer. I used heavy paper to make templates for the fiberglass cutouts, applied a bead of RTV around the edge after laying it on the cloth, and smoothed it with a piece of cardboard. When one side was dry enough not to be sticky, I turned it over, replaced the template, and spread the RTV here in the same manner.

Magpie - 7-4-2015 at 10:57

Since I only applied the bead on one side the other side is almost bare. But neither blanket has frayed in the years I have been using them. The big one is 1' x 2'. And I have a smaller one but can't measure it right now as it is in use. :D

I normally work with 19/22 size glassware. So, if your normal glassware is 24/40 you might want bigger blankets.

Edit: The smaller blanket is 1' x 1'.

[Edited on 7-4-2015 by Magpie]

Loptr - 7-4-2015 at 11:35

Quote: Originally posted by careysub  
Being able to buy locally is convenient, but you can also easily order it.

Aircraft Spruce (local for me) ships a variety of fiberglass fabrics everywhere. Particularly useful I think is fiberglass tape, it is selvage edged and so does not fray and which can be wrapped around most anything.

http://www.aircraftspruce.com/categories/building_materials/...

Soller Composites has fiberglass sleeving which may be useful as well:
http://www.sollercomposites.com/composites/carbon%20fiber%20...

They have in the past also had basalt sleeves which are also very high temperature, but do not currently seem to have any stocked.


These are excellent suggestions.

I have ran a couple reactions so far, nothing noteworthy, and primarily testing out my glassware and other equipment. Once I feel comfortable with my setup and feel I have applied as much risk management as is needed to curb my own concerns, I plan to start documenting my efforts here.

The reason I have now focused on thermal blankets is the difficulty I have had with keeping the reaction flasks and columns a uniform temperature, especially in cases where I am not looking for a gradient necessarily, and just want something distilled off as quickly as possible. Also, since I am not using a heating mantle, but rather a hot plate, I am trying to minimize heat loss and increase the effectiveness in getting the flask up to temperature.

I have been going through and attempting purification of solvents that I purchased from the hardware store. A preparation of fuming nitric acid took forever just to condense approx. 75 mL, which I could tell was from an issue with having a consistent temperature from the flask to three way adapter.

I am working with a Corning PC-420D, by the way, brand new when I acquired it, and I know it works very well. I probably should observe the surface temperature of the hot plate just to watch for any variances, as I guess I could have power issues. (I was observing the temperature at the top of the three way and not the flask, and noticed variations in the temperature of the vapor as it came over--nothing significant, but it would speed up and then slow down, and then repeat all around the same temperature.)

Zombie - 7-4-2015 at 14:43

It also works well wrapped around you columns as both an insulator, and as a safety blanket if a column should break.

It's easy to wrap a column 2 layers thick, and silicone the edge together.

Stainless steel wire also works to wrap, and twist tie cloth.

I buy this in 300 lb. rolls so I have glass coming out my ears. I use it for more things than I can list including packing my exhaust on my race scooters.

I like the ideas presented here.;) Quite a clever lot!

subsecret - 7-4-2015 at 16:21

I made a blanket that looks like the outline of a pair of pants, or a very square "U." This way, I can wrap it around the neck of a flask, and bring the two "legs" across each other. This forms a conical shape that covers the entire top of the flask, while the neck protrudes from the now triangular groin area of the cloth.

Magpie - 7-4-2015 at 17:13

Quote: Originally posted by subsecret  
This forms a conical shape that covers the entire top of the flask, while the neck protrudes from the now triangular groin area of the cloth.


Nice.

I have thought of making a blanket with a small window near the top so you can check on the progress of the reaction, distillation, etc.