Sandblasting - Harbor Freight Compressor

[heimlich]

Will this sandblaster allow me to do the entire body inside and out along with the pan?

https://www.harborfreight.com/air-tools/air-compre...67847.html

Is it recommended to purchase the warranty they offer when purchasing it?

[EverettB]

In the big scheme of things I know very little about air compressors but enough to know that compressor won't supply near enough air to do squat for sandblasting.
I have a 25 gallon compressor and it can barely keep up with soda blasting small parts.

My understanding is you need a 60 gallon tank minimum.

Search on sand in the compressor thread, I believe some information comes up.
Direct sand search link there
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[heimlich]

[Evil_Fiz]

Although it is technically possible to blast the entire car with that compressor, you will find the time involved is not worth the effort. The low air volume delivery of that compressor would increase the amount of time needed to deliver a given amount of media. That would in turn make the compressor run non-stop after the first minute of blasting which will lead to an overabundance of water in the lines. You would need an aftercooler between the pump and the tank followed by a water separator/trap or about 50' of metal pipe with a water trap at the end after the tank to help reduce the condensed water in the lines. Both of thees options are a good idea no matter what compressor you choose. Research them both to help you decide which is best for you. A desiccant air dryer would help remove any moisture remaining in the air stream.

My old compressor had the following specs:
PSI: Max 125
Tank: 20 Gal.
Displacement: 14 CFM
Air Delivery: 10.3 SCFM@40PSI / 8.5 SCFM@90 PSI
I used this compressor to blast my pan but it was a slow and frustrating effort. I was using a 50# siphon feed media balster with crushed glass. I could get through 1 50# load of media then the amount of water in the line would begin to clog the blaster.

The conventional wisdom is to get the biggest compressor you can afford and/or fit in you work space. Although true it is not always necessary. large capacity will reduce the amount of time the pump runs but what you are really interested in is air volume and duty cicle. I got away with 8 CFM @ 90 PSI. If I had installed an aftercooler or a condensation loop, I believe I could have successfully done more work with less frustration.

One way to achieve high CFM with low cost equipment is to chain several small compressors together.
here is one example: https://www.youtube.com/watch?v=YGYgQO5TFto

Here are some examples of an aftercoolers:
http://blog.cnccookbook.com/2011/09/06/aftercooling-a-compressor-to-cut-down-on-moisture/
https://www.youtube.com/results?search_query=compressor+aftercooler

Here is an examples of a water separator/condensation loop:
https://www.youtube.com/watch?v=VFFPIRLx_ro

...and desiccant dryers:
DIY using Galvanized pipe: http://www.garagejournal.com/forum/showthread.php?p=4128720#post4128720
DIY using a Whole House water Filter (Silica gel is a better desiccant choice): http://www.cnczone.com/forums/articles/212488-cnc.html
Retail (DeVilbiss QC3 Air Filter and Dryer): https://www.amazon.com/DeVilbiss-130525-QC3-Filter-Dryer/dp/B002PR8ZXK

Your choice of media blaster will also influence how smoothly the process will go. A siphon feed unit is small and portable but will use more air/pound of media than a pressurized media blaster. The pressurized units can be had at Harbor Freight for around $100 US or on Craig's List for a bit less. If you build a blasting booth out of PVC and plastic sheeting you can cut down on the amount of media needed to blast the entire car because you can reclaim and reuse the media several times before it becomes too fine to be be effective. I found that the Glass media sold at Norther Tool ( Clean Bite Crushed Glass Blast Media — 50 Lbs., Medium Grade
Item# 49360) will last about ten uses before it is too fine to use. This media is also safe as it contains non-crystalline silica and will not lead to silicosis, but a respirator is HIGHLY RECOMMENDED.
Here is an example of a blasting/painting booth: https://formufit.com/pages/pvc-spray-paint-booth

...we're all in this together.
Emil
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[vwjetboat]

nope... compressor would run the whole time and last about 4 hours before burning down.

[heimlich]

The price of the compressor is what is getting me. It seems I will need to spent over $800 in order to be able to do this. If I do that, I may as well try painting the vehicle too.

Thanks for the input.

[vwjetboat]

[heimlich]

I've got two cars to do. Each one is about $1000 to paint at the shop I take it to. I'm assuming the paint cost to be around $500 of that but I am guessing.

If I took the 2k I was going to use to paint and bought the tools for myself I could warrant the cost of the large compressor.

[vwjetboat]

[Evil_Fiz]

Here is the compressor I purchased to replace the aging "Tank of death" 20 gal. compressor I was using.
NorthStar Belt-Drive Stationary Air Compressor — 3 HP, 60-Gallon Vertical Tank - $569. It is the Northern Tool house brand but appears to be made by PUMA: (Puma 3-HP 60-Gallon (Belt Drive) Single-Stage Air Compressor. It is $130 cheaper than the PUMA and carries a 4 Yr. warranty if used in a noncommercial setting; both units have overwhelmingly positive reviews. It will deliver 11.3 CFM at 90 PSI and 12.5 CFM at 40 PSI, more than enough to media blast and paint with an HVLP gun. They also offer free delivery if you don't need lift gate service or free delivery to your local Northern Tool store. You may also find an on-line coupon code for $50 off a purchase over $250 (google "Norther Tool coupon code.")

I hope the info is helpful
Emil
_________________
“…It's not just about what's interesting. It's also about what's helpful, and it's helpful even if it helps just one other guy working on a Ghia.”
kiwighia68

See my build on TheSamba at:
The K_R_A_K_E_N_N : a 70 Ghia Convertible reinterpreted

[heimlich]

That's a lot better than the $800 I thought I would need to spend. Thanks.

[heimlich]

I purchased the Northern Tool One.

In order to get started I see I will need at least the following:

Regulator
Sand Blaster Tank
Air Hose
Respirator

Is there anything else I might need and is Harbor Freight a good place to get everything else?

[fabricator john]

to sand blast a body inside and out will kill any home type compressor , save your headache and just have it blasted.
fabricator john
you should be able to have it done in the 3-500 dollar range

[theKbStockpiler]

When I have to replace my 5hp 20gallon compressor it's going to be with this if I can't find a 6-6.5 single phase.
http://www.homedepot.com/p/Puma-40-Gal-5-HP-Electr...lsrc=aw.ds

-A bigger tank only stores engergy.
-Blasting at high pressure warps sheetmetal
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[heimlich]

[Evil_Fiz]

[theKbStockpiler]

[buguy]

You should just have it done. It takes a ton of volume to blast a car. Then you have to get something on the metal immediately or it will start to rust.

[heimlich]

I'm sand blasting it then spraying it with primer. Then I will take it to the autobody shop and let them deal with it. I've got at least two cars to do like this. If I paid someone to do it I would pay more than the tools I bought. Now I get to keep the tools at the end for other things. Maybe I will even try spraying it myself.


Thank you for all the points. It's interesting to see everyone's view points.

[buguy]

You should try spraying it for sure.
Do you know what your going to spray it with? A direct to metal material I hope!