Isopropyl Alcohol instead of DeNatured Alcohol

Has anyone used Isopropyl Alcohol instead of Denatured Alcohol to wipe down Epoxy resin in between coats? Is it better?

 

I wouldn’t do it.  I’m no expert, but I think you could create your own set of problems if you do.  I’m thinking your coat of Epoxy will “cloud up”.

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Better?  No, cheaper yes

 

isoproply alcohol is either 30% or 9% water and I have had the surface go cloudy then require scotchbrite and water and once or twice 400 grit and other times no issues whatsoever.

  Humidiy present during cure seemed to  a big factor in this post wipe cloud up. rather than experiment to figure out exact  influencing variables,  I just don’t let IPA touch recently hardened epoxy.

 

I’ve used it though the 91% with little issue, but not wiping weave for a fill coat.  I mainly use it when i do not want to use gloves or it is all I have handy.

 

As far as wiping non surfboard objects pre epoxy, I find the DNA can clean what the IPA cannot.

Thanks for the replies.

We used Isopropyl on electronic equipment because it doesn’t leave residue. Denatured is supposed to leave a harmful residue. I may try a test and see.

My daughter asked me to get some rubbing alcohol (IPA) so I told her I had denatured, but she said she wanted the Isopropyl. I actually think it may cost more for the same volume. I also don’t like the smell of IPA.

 

 

Seems that all DNA is not the same depending on the denaturants chosen.  

 

 

 

 

I’ve used 91% iso for years to wipe down pre gloss and it works great. Never see any residue and it evaporates quick right after I do a good wipe.  

That’s good to hear. I’m going to try it. Not sure if I’ll make it a regular thing.

Dawn Dishwashing Liquid.  Keep it simple.

Sorry to revive this, but I have read lots of threads and wanted to ask this…

I am using poly only, no epoxy, so after sanding the laps and nose grinding etc, i usually wipe with a rag with acetone on. Is that ok, or should I be using denatured alcohol too?

Thanks

After you have ground the laps and are ready to hotcoat, you should not wipe the board down with anything.  If you do it will get super sticky and make it harder to spread you hotcoat.  Also any subsequent layers of cloth for logos, tail patches etc will give you problems.  The only time you would use acetone to wipe a lamination would be to remove dirty finger prints, which shouldn’t be there to begin with.  Use a paper towel wet with a little acetone.  Professional glassers don’t wipe a laminated board with anything.  They go straight to the hotcoat ASAP.  If you let a laminated blank sit around for weeks or months and it loses tackiness, you can wipe it down with acetone to make it tacky and thereby insuring that the hotcoat sticks.  I am specifically talking Poly here.  But I do not wipe down Epoxy either.

Ha, that’s interesting thanks. I thought everyone wiped like mad (like I do!). LIve and learn!

One question… when you’ve ground the laps etc, don’t you get bobbles and bits/dust which need removing? I usually blow what I can shift with air gun, then wipe/dab to get the rest off. How do you deal with the mess left by sanding/grinding? thanks

I  blow off any dust and proceed.  The cleaner the lap when you glass, the less grinding needed.  I often don’t even grind the top cloth lapped onto the bottom.  Just hotcoat and sand.  Work harder and be more diligent at getting your laps to lay down.  Use a hard plastic squeege to pull the resin off the lap.  Give yourself more set time to work the laps.  A cleaner lap on the lamination is the ticket.

Don’t wipe it down with any chemicals.  This causes more problems than helps with.

Chemicals also wreak havoc if you’re doing any pin line work.  It picks up the colored dust and creates a colored paste that just spreads to pin holes etc. Almost impossible to correct. 

The board will be at its most sterile right after each sanding phase.  The problem is usually touching the board with bare hands, especially with epoxy during.  When working with epoxy ( or poly), I won’t even look at board without gloves on during every stage.  I can’t emphasize enough, don’t touch the blank, board with bare hands.

Go easy blowing off with a compressor too.  They’re just contamination blowers - oil and water.  Quick few passes and you’re done.  Everyone obsesses getting every last dust particle off with a compressor and a tiny bit of dust usually isn’t the issue (until glossing).

Also stop wiping boards with any type of rag too.  Especially in prep for glossing. The lint is a huge problem.   Use the tape method - drag the sticky side of tape up and down the board a few times instead. 

 

Also a lot of pros say washing the board in between layers is a waste of time.  My guess it’s doesn’t hurt, but again handle it with gloves.   

Avoid blowing dirty/oily/wet air by using a vacuum cleaner instead.  Use a nice clean (or new) brush attachment with a good vacuum and you can remove a lot of dust.  Air will be as clean, dry and oil-free as that in the room around you.

I agree about wearing gloves for epoxy – handling shaped foam and fresh-cured or sanded epoxy.  I wear dishwashing gloves for sanding foam (especially XPS) and while sanding epoxy to keep hand oils off foam and glassed surfaces.

I have used window glass cleaner on FG surfaces as a degreaser, wipe off then wipe down with water (ideally distilled) dampened, lint free cloth/absorbent paper before sanding and glassing.  I use 90% isopropyl  wipe down followed by a water (ideally distilled) wipe down on XPS foam before shaping.  (XPS foam is totally closed cell and non-absorbent).

Yep I did a fairly decent job, glassed this board last night. With a stupidly difficult (for me) colour job, it was a living hell. I mixed up literally 0.5% mekp max to extend working time, it still went off before I was totally happy but so be it! I have to say though, the “pressing” the lap line into the foam is a great idea, first time I have tried that and wow why didn’t I think of that before! I used to mess up the foam with my 3M disc on the laps! Now I just have a bump on tip of nose and two on tail to deal with. I think I am improving but the tips in here sure make that faster.

 

Thanks. Yes it sounds like I obsessed and wiped down too much in the past then. I do use compressed air as I use that a lot for other stuff but its filtered and water separated and comes from 50 yards away in a clean environment.