Casting Pressure Pot or heat gun?

[Bleedaggie]

Went to woodcraft yesterday to buy a pressure pot. They didn't have the 2.5 gallon pot but the guy in there told me if I didn't want a pressure pot for any other reason (ie painting) I'd be better off to buy a heat gun - that they're cheaper and would get the air out of blanks just the same.

What say you all?

 

[jttheclockman]

Do not do it. Heat guns trick is for when doing large table like pours where the resin is exposed. Running a heat gun over it will heat the resin and can release bubbles. But for casting the resin is contained in an enclosed receptacle so no way to get at all the resin especially if you are doing vertical casting in tubes. I highly and mean this highly if you are going to do casting please get a CAT pot ( California Air Tool) Just decide what size you think you need. and that depends on what you plan on doing.. Just ask here for suggestions. I recently bought the 2-1/2 gal version and glad I did . So much safer and easy to use with no need to add parts like with a HF freight one. If you go to a 5 gal or larger they come with wheels because they get hefty. They are built like a tanks and designed for us casters. Check them out. yes maybe a little pricey but if you are serious, safety first. pressure pots is no joke to play with.

 

[Drewby108]

Even with open pours, it is so easy to mess up your casting by overheating spots with a heat gun. It can cause ripples in the resin as some spots cure differently than the area around them. On wide area or colored pours this isn't a huge deal, but if you are doing a clear casting, it shows.

 

[JohnU]

I would guess they don't have "casting experience " and are confused with their resin. They've probably seen videos of thin epoxy pours being heated with a heat gun or torch. Deep pours are different and pressure will compress the bubbles so they aren't visible.

 

[PreacherJon]

Went to woodcraft yesterday to buy a pressure pot. They didn't have the 2.5 gallon pot but the guy in there told me if I didn't want a pressure pot for any other reason (ie painting) I'd be better off to buy a heat gun - that they're cheaper and would get the air out of blanks just the same.

What say you all?

I agree with JT. Sometimes those guys that work in Woodcraft and Rockler don't know anything other than one or two specialities.

 

[Curtis]

Do not do it. Heat guns trick is for when doing large table like pours where the resin is exposed. Running a heat gun over it will heat the resin and can release bubbles. But for casting the resin is contained in an enclosed receptacle so no way to get at all the resin especially if you are doing vertical casting in tubes. I highly and mean this highly if you are going to do casting please get a CAT pot ( California Air Tool) Just decide what size you think you need. and that depends on what you plan on doing.. Just ask here for suggestions. I recently bought the 2-1/2 gal version and glad I did . So much safer and easy to use with no need to add parts like with a HF freight one. If you go to a 5 gal or larger they come with wheels because they get hefty. They are built like a tanks and designed for us casters. Check them out. yes maybe a little pricey but if you are serious, safety first. pressure pots is no joke to play with.

 

[leehljp]

Some sales people are very knowledgeable, however many, if not most are there to make sales any way they can. After all, that is their primary purpose.

google/search engines and user sites such as IAP are the best place to find out the truth in context of use. As one guy who regretted not following my recommendation (in a computer purchase) a few years ago said: "Well, the reason I didn't buy what your suggested was that he was the salesman and I figured he had more experience than you!" Me: "Most salesmen are there to sell what they have on hand or whatever they get the most commission out of. But a few will be honest with you. Your knowledge, experience and prior research should tell you the difference."

 

[KenB259]

Some sales people are very knowledgeable, however many, if not most are there to make sales any way they can. After all, that is their primary purpose.

google/search engines and user sites such as IAP are the best place to find out the truth in context of use. As one guy who regretted not following my recommendation (in a computer purchase) a few years ago said: "Well, the reason I didn't buy what your suggested was that he was the salesman and I figured he had more experience than you!" Me: "Most salesmen are there to sell what they have on hand or whatever they get the most commission out of. But a few will be honest with you. Your knowledge, experience and prior research should tell you the difference."

It blows me away how many people don't grasp the fact that salesmen are where they are to sell you something. Do your research and take what a salesperson says with a grain of salt.

 

[Kevin Rappold]

Went to woodcraft yesterday to buy a pressure pot. They didn't have the 2.5 gallon pot but the guy in there told me if I didn't want a pressure pot for any other reason (ie painting) I'd be better off to buy a heat gun - that they're cheaper and would get the air out of blanks just the same.

What say you all?

Just want to put in my two(2) cents.

Pressure over heat? Hmmm. Don't agree with that. I will say that I heat the molds prior to pouring clear. It seems to make a difference. As far as buying a pot, I went to harbor freight and bought a 2-1/2 gallon pressure pot. I had to make very minor changes to the piping…Mainly for my own convenience. Anyhow, I've used it for over two years. It has done everything I've needed and it's worked well. Of course it's all about getting used to working with your own piece of equipment and how comfortable you are with making your own modifications . If you aren't comfortable with adding/changing piping, spend more money and get one ready to go. I'd also go on to say that "pressure" means just that!! Safety is #1 or else there will be no turning….

I'd go to YouTube for more details.

 

[jttheclockman]

Just want to put in my two(2) cents.

Pressure over heat? Hmmm. Don't agree with that. I will say that I heat the molds prior to pouring clear. It seems to make a difference. As far as buying a pot, I went to harbor freight and bought a 2-1/2 gallon pressure pot. I had to make very minor changes to the piping…Mainly for my own convenience. Anyhow, I've used it for over two years. It has done everything I've needed and it's worked well. Of course it's all about getting used to working with your own piece of equipment and how comfortable you are with making your own modifications . If you aren't comfortable with adding/changing piping, spend more money and get one ready to go. I'd also go on to say that "pressure" means just that!! Safety is #1 or else there will be no turning….

I'd go to YouTube for more details.

I can add to this and not to disagree with poster but, the difference between HF and CAL pot is absolutely night and day. I used the HF pot for over 15 years about. It served me well. They over the years either changed the place made (all from China) or the quality and todays HF pot is not as good one from 15 years ago was. Just look at the rating on the pot. Those hold down handles are just not as stout as the ones on the CAL. pot. I too redid mine and actually was going to use for both pressure and Vac. But never gone down that route. yes the Cal. pot is more expensive but in time it will save you big time. Plus to me safety with those tools is paramount . I wish I had converted sooner. Please do your homework before buying and enjoy the hobby. Good luck.

 

[egnald]

Just chiming in with my 2 cents as well. I always try not to be too hard on sales people as they couldn't be expected to have much expertise with all of the tools and technology available. I think most are genuinely doing their best to help customers solve problems and are really not in it to just make the sale.

There is some really good information in the prior posts about heat and pressure. I can only comment based on my personal, and somewhat limited, experience with casting. First of all, for blank casting I have only used Alumilite Clear Slow which I think may help with reducing bubbles as it is in the liquid state longer so there is more time for bubbles to float to the surface and more time for the pressure from the pressure pot to do the magic it does on them. As for epoxies and other kinds of resins, I simply don't know.

I have been successful without heating my molds. I use homemade molds made of Schedule 80 PVC pipe and I just haven't found a simple enough way to heat them up before use. Maybe I'm missing out on something and will figure something out some day, but so far - so good.

I use a 2-1/2 gallon California Air Tools pressure pot. I never had a Harbor Freight pressure pot, but I know it is designed for use as a paint pot and not as a pot specifically for casting like the California Air Tools pot is. I know it was about double the cost but from my experience, it was nice not having to fiddle around with the plumbing or anything else. I have also heard that some folks struggle with getting the Harbor Freight pots to seal well, but that's just hearsay. My California Air Tools pot has worked just great - right out of the box.

And, finally, casting my own blanks has been a thrill. I'm so glad I decided to jump in and only wish I had done it sooner. It's been great fun with more to come.

Regards,
Dave

 

[JohnU]

Pressure over heat? Hmmm. Don't agree with that. I will say that I heat the molds prior to pouring clear. It seems to make a difference.

It absolutely makes a difference. I think the original question was if heat could replace pressure, and in any pour thicker than a bar top sealer it can't. Both heat and pressure are very useful in casting.
Heating material prior helps the resin adhere to it without pulling away, and heating the molds will help you keep the shape of the mold without the resin pulling away from the corners.
Warming the resin prior to mixing will make it easier and quicker to get your resin mixed properly. Of course warmer resin also helps keep better color separation but that's a little farther in the process.

Pressure will not make air float out, it compresses the air bubbles so you can't see them. In my opinion, pressure should always be used if possible, no matter the resin. It's just another step in the process to help the success of the cast.

So both are essential not a replacement for each other.