Galvanized metal concerns/RTV

[smokin geese]

Again, I am new here... I have a post a that is just a few posts down...new freezer build.  I have been reading alot of posts on the freezer/fridge builds.  I guess I did not realize galvanized metals gave off a poisons when heated up.  Alot of great responses to this concern.  I went back to 2010 comments on this. 

I currently have a  4"x3", 10"x15" (top of the inside smoker) and 4 - 22'x2 1/2" and 4 - 60"x2 1/2" (inside door jamb) galvanized pieces inside my smoker that I just installed.  The 2 smaller pieces of metal are covering holes in the top of the inside of the smoker and the 8 pieces are covering the small openings on the inside of the door jambs where I removed the plastic moldings from.  I will be removing all of these pieces and hopefully installing aluminum.  I think I will use aluminum flashing I can buy at a local hardware store for all of this.  Maybe double up on the pieces of aluminum for thickness.  I just hope the aluminum gauge is thick enough.  If it wasn't for all the postings on this web site about this I would never have caught this!  I don't need family and friends getting sick over this.  A little more work but I don't want to have to worry about this. 

(I read comments on this subject too!) RTV 4500 Sil-Bond is what I am using states:  Fully cured sealant is non hazardous.  At extreme temperatures product can form formaldehyde vapors and is a potential cancer hazard and skin and respiratory sensitizer.  Max temp use 400 degrees.  FDA CFR 177 2600, USDA.  Should I be using a different RTV?  

Thanks everyone!   Any other suggestions that I haven't thought of would be appreciated.  I hope everyone has a GREAT Holiday Season!           

 

[duanes]

I used Permatex high-temp RED RTV Silicone #26BR for propane smoker door gasket.  It is rated at 650 degrees Fahrenheit.  It does not generate any off gases once cured as long as you don't exceed the temperature rating and the package explicitly stated it was food safe when cured.  If you know you will not exceed the 400 degree rating on the RTV you have now, you should be fine as long as it is fully cured.

 

[venture]

Lots of controversy on galvanized and how hot it has to get to be a problem.  I just try to avoid it so I don't have to get a headache trying to figure out the science.

Good luck and good smoking.

 

[puddy]

I know of a few welders that got really sick after welding galvanized. That being said I will not gamble on my family's health and safety by using galvanized steel. IMHO rip it out replace it with plain old sheet metal and if you are worried about how to affix it I would use either sheet metal screws or rivets.

 

[roller]

If you use it it may make you act like me and you really dont want that..My first smoker was made from galvanized  30 gal trash can...It was back in the 70`s I did not know better used it for several years..But I would not use it now...NEVER !!!!  And my children all have college degrees...

 

[jftx]

I used Permatex high-temp RED RTV Silicone #26BR for propane smoker door gasket.  It is rated at 650 degrees Fahrenheit.  It does not generate any off gases once cured as long as you don't exceed the temperature rating and the package explicitly stated it was food safe when cured.  If you know you will not exceed the 400 degree rating on the RTV you have now, you should be fine as long as it is fully cured.

How do you cure it? 

 

[dward51]

I've often wondered at what temp does the problems with galvanized metal start.  Yes, I've heard the stories about welding galvanized steel.  Big difference in temp when welding though. With the possible exception of a firebox, I don't think you will see a temp high enough to matter in a smoker.  And I would think it would be like the inside of an old tank or drum and once you "burn it out" good", a galvanized expanded metal charcoal basket might not really matter either.  No scientific data to back me up, just a UWAG (uneducated wild ass guess).  

But I confess, I'm chicken and don't want to tempt fate either.

 

[linguica]

[h3]Toxicity[/h3]
Although zinc is an essential requirement for good health, excess zinc can be harmful. Excessive absorption of zinc suppresses copper and iron absorption.[sup][170][/sup] The free zinc ion in solution is highly toxic to plants, invertebrates, and even vertebrate fish.[sup][189][/sup] The Free Ion Activity Model is well-established in the literature, and shows that just micromolar amounts of the free ion kills some organisms. A recent example showed 6 micromolar killing 93% of all Daphnia in water.[sup][190][/sup]

The free zinc ion is a powerful Lewis acid up to the point of being corrosive. Stomach acid contains hydrochloric acid, in which metallic zinc dissolves readily to give corrosive zinc chloride. Swallowing a post-1982 American one cent piece (97.5% zinc) can cause damage to the stomach lining due to the high solubility of the zinc ion in the acidic stomach.[sup][1[/sup]