Wavy epoxy...

[doug hodder]

In a previous thread it was discussed about the waves that you can get in epoxy, especially when laying it down on something like ACX ply. To demonstrate this, I took a piece of MDF and put some sandpaper on it and just lightly sanded the side to hit the high spots and really show what we were talking about. Plywood is run through a sander and isn't typically really flat due to the grain, not like a finished veneered ply, the grain in it will take on epoxy differently, leaving high and low spots till it's sealed off and filled.

This shows a couple of coats of epoxy laid down on top, the first one really soaks in, so I mix in some fairing filler in it (red colored) to minimize some of that...It isn't pretty as a lot of the time, I use all my left over epoxy from other steps and smear it on the ply, with a plastic spatula, hence the sag in it, lower right, the rest is in the ply...This portion hasn't been faired out as I had the fender temporarily mounted and couldn't work this area. It'll all be done up smooth.



Here's what I use to flatten it all down...mostly hard rubber blocks, get the ones that allow you to use a equal portion of paper so you don't waste any sand paper, the air file (straight line sander) can be bought from HF and will cut it really fast, but it's an air hog on the compressor...little compressors won't keep up with it... Doug

[apratt]

Doug, that is not a HF board is it. Looks like a Viking air boar, they are very good tools. A little spendy for the average person. I think I have 4 of them!

[doug hodder]

Arthur...bought that one at a local discount tool guy...less than 60$, which is probably why it uses so much air...I don't use one that much so didn't get a really nice one...closer inspection on the name plate says Devilbiss...made in Taiwan...Doug

[apratt]

Oh!! they must be coming out with so many clones, it is getting hard to tell them apart. Yea $60 is much cheaper. 3 of mine bought new and have since rebuilt 2 of them and the forth one I bought used. In the body shop I use them day in and day out, so gotten a lot of miles out of mine. Needed good ones that I can depend on. But for most people I am sure the HF are a fine air boards.

[asianflava]

I think all those jitterbugs are air hogs, they need a lot of volume. I never enve bothered to look into them because I know my compressor won't keep up.

[apratt]

For the air board you need at lease 4 cfm of air. The DA sanders they don't use nearly as much air, but they don't produce a good flat surface.

[doug hodder]

Arthur...I must have jinxed myself...today the air board locked up and finally died...I did go get another...this time I bought up. I bought the first one on the first boat and "thought" I'd use it...2 boats, 3 tears, and several car and truck paint jobs later...yeah...I use it, enough to wear it out, at least a cheap one...I bought a Hutchins Hustler...like running a Porsche compared to what I had...Doug

[Kevin A]

Arthur...I must have jinxed myself...today the air board locked up and finally died...I did go get another...this time I bought up. I bought the first one on the first boat and "thought" I'd use it...2 boats, 3 tears, and several car and truck paint jobs later...yeah...I use it, enough to wear it out, at least a cheap one...I bought a Hutchins Hustler...like running a Porsche compared to what I had...Doug

Uh oh, looks like the Doug Zone has moved on to airboards.
Hutchins Hustler eh? nuttin like buying the best...
We have an older hutchins that we use for cleaning gasket surfaces on blocks and cylinder heads.

[doug hodder]

Kevin...I used to buy tools to get by....but found that you get a lot more quality work out of a quality tool...it'll be the last one I ever buy. Doug

[apratt]

Hutchins is one of the better brands, very good. If you buy quality tool you can have them rebuilt when they get "tired". But if you don' t use the tools a lot like every week or so then the cheaper ones are the way to go for some people, nothing wrong with that. But like Doug said when you get the better quality ones they sure work a lot smoother, you can tell the difference!


p.s. Doug sorry to hear yours konked out, they seems to do that when you talk about your tool. Sure hope mine don't decide to do that. I have too many air tool, but will never part with any of my tools. I am addicted to tools ( Tim Allen the tool man)

[doug hodder]

Arthur...what is your preferred brand on a DA? It's tired also...and a big plus is that the new sander doesn't hammer by wrists like the old one did...something to think about as I am approaching my golden years... Doug

[prohandyman]

Doug
Are you putting the epoxy on the surface while it is verticle or laying it down horizontal?
Dan

[doug hodder]

Dan...it will do it either way...I put the first couple of coats on flat before I stand up the sides...on this one however...that sag that is showing is from where I just mopped on some extra leftover epoxy from another step I was doing. I put it on with a roller and tip it off when I do a whole side. the other "waves" are from the epoxy penetrating into the ply...really penetrates in some areas depending on the grain and doesn't in others...that's what starts the wave. Doug

[apratt]

Arthur...what is your preferred brand on a DA? It's tired also...and a big plus is that the new sander doesn't hammer by wrists like the old one did...something to think about as I am approaching my golden years... Doug

Doug, my prefered brand on the DA is Hutchins. I have the 4500 model, it runs like a Cadilac compared to my old Rodac. LOL. It dosen't put your hand to sleep from all the viberations also it seem to give me a smoother surface not nearly as much dips and gouges. I have also used Chicago pneumatic, Blue point. But still like the Hutchins the best.