What's your experience with power fairing boards?

Discussion in 'Boatbuilding' started by CatBuilder, Apr 28, 2012.

  1. CatBuilder

    CatBuilder Previous Member

    I need to get my project moving. I have an employee who is good with a long board, but we are not making the progress I want to see - and there is a whole lot more fairing to come, including doing high build primer and such.

    So, in the interest of saving money on rent, car breakdowns and hourly wages, I am looking at getting some power fairing boards. The bonus is I can also use the same compressor and HPLV guns to spray the boat, saving a ton of cash.

    Does anyone have experience with these?

    Here are some of the types I have found:




  2. CatBuilder

    CatBuilder Previous Member

    And... does anyone know how to properly size a compressor. It's not something I've done before. I see 11-12CFM @90 PSI on these tools.

    Does that mean I need a compressor to run 24CFM @90 PSI continuously to run a pair of them, or does the tank take up some slack??
  3. CatBuilder

    CatBuilder Previous Member

    Random Orbit or Linear Action?

    Talking to myself here, but I understand the compressor sizing now.


    What is better for fairing?

    A random orbit action or a linear action?

    It seems like it would make no difference to me and that I'd prefer linear action because it tends to take more off due to having a long stroke, but what do you guys think?
  4. Stumble
    Joined: Oct 2008
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    Stumble Senior Member


    I the hands of an expert they are incredible tools. In the hands of an armature they can very quickly take off more material than desirable, much more. I have seen experts use them to fair a hull to the point all it needed was a skim coat of epoxy and some 80 grit, and I have seen others use them and require major surgery to replace what was removed.

    Personally I would start with a good random orbital sander and just accept it will take me longer to do, but at much less risk of major screw ups.
  5. CatBuilder

    CatBuilder Previous Member

    Actually, Stumble, a random orbit sander can't work at all. It's too small. It can't feel the highs and lows across a large enough area to be useful. It will just follow the unfair curves.

    This company does have orbital boards and linear action power boards though. That's what I was trying to figure out in my last post.

    I am wondering if linear action is the way to go since with a 1" stroke, it would seem to remove more material. The random orbits I have used in the past were painfully slow, so I'm assuming the random orbit boards are too.

    I'm not really worried about any screw ups. My employee has 15 years in the boatbuilding industry and I have hundreds of hours on the long board now too.

    We need speed, not precision. We are already experts. Unfortunately, any of the higher primates can do this work. It's a no brainer. I am just trying to find ways to speed it up.
  6. Saildude
    Joined: Jun 2011
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    Saildude Junior Member

    I think it was a random orbital that I used on my cockpit last year - air powered about a 12 inch dia pad. Bit of a handful to use - had to be real careful to not get onto areas that did not need to be sanded.
  7. CatBuilder

    CatBuilder Previous Member

    That sounds good, Saildude! :)

    I'm looking for power. ha ha ha

    Of course, you can do the finest delicate jobs with these too, given that you just change the paper to the appropriate grit.

    So yours was probably the round pad type? I'm looking at 16" long power board so they can feel the highs and lows fairing a new hull. I may even go and fasten a 36" x 4 1/2" board to the 17" stock surface on the power board. That way, it can hit bigger areas. 17" still seems too small to me.
  8. Saildude
    Joined: Jun 2011
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    Saildude Junior Member

    yes the one I borrowed from the yard was round - I would expect the flat long ones would work but as noted above - in the hands of someone that was not skilled or grit that was too coarse or a person that was a bit impatient the power anything can be really bad.
  9. mydauphin
    Joined: Apr 2007
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    mydauphin Senior Member

    Sorry, I haven't been answering, I have not been feeling well. The power sanders are fine, but not long enough. Depending on boat you use a 3, 4 or 6 foot board. Then I use a 3 foot board to sand. If you did your job right the first time not much sanding. Use paint between layers to see were you need sanding more. add colors to epoxy so you can see work. Then you can use those smaller machines.

    Compressor should be much bigger than tools you use so it can rest, (cycle) you don't want it running 100% duty cycle. The whole idea of fairing is to sand as little as possible. You should be able to do start to finish in under three coats. You can rent a big compressor for little money.

    Again fairing a boat is not about power sanding, but spreading the right amount of putty.
    There is a company here in Miami that makes a good fairing compound. It smooths with water so I being able to do some jobs in one coat, almost no sanding. http://www.fascoepoxies.com/ They make there own stuff here, and the formula have been around for several decades. I have used them for 10 years. They have several different epoxies for just about everything. Their fairing compound is about 40 a gallon I believe.
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  10. CatBuilder

    CatBuilder Previous Member

    Hope you are getting better...

    We have been using 3 foot (by 4 and 1/2") long boards to manually fair the foam first, then infuse the fiberglass onto a near-fair surface, then final fair with a layer of microballoons no more than 2mm 1/8" thick. Some dips we had to do were 3mm or well less than 1/4" - much closer to 1/8".

    We did the keel of one of the hulls with that microballoon setup and it's just about ready for some high build primer (assuming that's the next step, which I'm not even entirely sure of).

    We use the grit of the sandpaper to see where the high and low spots are. With a hand run long board, you end up seeing where the grit just scratches the surface of a low (while resting on two highs) and stop there for a slight fill. For overall fairing we also use a batten and mark highs and lows to be focused on.

    I am assuming I can go from microballoon epoxy bog right to high build primer with some imperfections in smoothness (but none in fairness) and be fine. Is that correct?

    Then we fair the high build primer and it's time to paint the topcoat and then clear coat?

    That's like 4 more sandings of the hull to get there, so I need some power tools for that. (while increasing the grit to keep a fine cut) I think, anyway.

    Got that now. I'm looking at an 18.1 CFM compressor to run a pair of 6.2CFM power long boards. The other use for the compressor will be as a driver for an HVLP spray gun, so I can't rent. It would be more expensive than buying when I figure how many months I need to use the thing.

    I have found it's a little bit of both. Spreading the right amount of putty is key (never glob it on), but when you are staring down the barrel of a hull that is 47 feet long and 8' tall, you need something more than just a standard longboard. Especially when you remember that a catamaran has 4 of these sections to deal with, plus a pair of 45' x 5' decks, plus a 16' x 16' deckhouse roof (and sides), plus transom stairs, two cockpits, etc.. etc... It's neverending. Then I have the inside to do after all that.

    I will look into the fasco right now. I understand System Three also makes Quickfair, which is supposedly fast.

    I just need to automate the process some. Even hiring a guy for fairing isn't enough. It's going too slow doing it by hand.
  11. mydauphin
    Joined: Apr 2007
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    mydauphin Senior Member

    I like the Fasco stuff for the price, and that I can go get it when I need it. I used Quickfair, it is very light but not that strong, not my boats I would not use it for big areas. I have my own system that I have develop, I basically sandwich fairing compounds in layers of pure epoxy. I work on larger boats and sometimes you have 1/2 and 1 inch in some areas. For decks I let self leveling aspects of epoxy do must of the work, I do the sides and let epoxy do the middle.

    To repeat an important point clear epoxy, fairing/ballons and then another layer of epoxy before final primer. It will make it stronger and less chance of cracking and more water tight. I used to work on Aluminum boats and the layers were followed religiously.
  12. CatBuilder

    CatBuilder Previous Member

    Thank you, Mydauphin.

    Very helpful post... very helpful indeed.

    Just because I already have it, I'll stick with the microballoons and regular old epoxy for fairing, I think. I will also be sure to paint a coat of neat epoxy over the fairing compound before final primer. Thanks for that tip.

    I am a babe in the woods here with understanding the various layers involved. I'm starting to get a handle on it, but it's not intuitive yet.
  13. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Random orbit (DA's) are smoothing tools, not fairing tools. In line sanders are fairing tools. Look for double action (duel piston) in line sanders and Hutchins makes a great tool.

    Most of these will need some modifications, such as larger pads. You can also do a reasonable job with a big buffer/sander, by adding a large, flexable plate to it's bottom and using PSA paper on it. I have a 10" that I do this with. It has a 20" square pad of 1/8" (good and flexible) and 1/4" (flatter surfaces) plywood attached. These are fast, but you better have a clue about what you're doing or you'll eat surface really quickly.

    The safest fairing is boogie board (long board) by hand. Next up is to bolt a palm sander to a bookie board, but make sure the palm sander has the switch for both isolating and back and forth motion (you want back and forth only). Next up from this is an in line sander, but again you'll probably need to make a larger pad for it. Further up on the list are the specialty, typically articulated sanders, which I don't like much.
  14. CatBuilder

    CatBuilder Previous Member

    Another fantastic post. Thank you, PAR.

    That's a good summary of what's out there and what the options are.

    Before buying the expensive Hutchins, I was thinking of epoxying one of my regular boogie boards (that's all we have used to date on the boat) to one of those smaller, 17" x 2 1/2" pneumatic, inline sanders like autobody shops use. They are only $29 at Northern Tool, so I could buy a dozen of them for the price of a nice Hutchins. I'll try that out first. If it works, great. If not, I'll get a pair of the Hutchins boards right away.

    Thanks for the advice. I'm just as shaky on this part as I was when I first started asking beginner epoxy questions on this forum. :)

    I don't mind painting, but all these layers upon layers is a bit overwhelming.

    Oh, and thanks for confirming what I was thinking: Orbital sanders are useless for fairing. It just didn't make sense to me to use that type of motion after physically dragging my torture board around the hulls for a couple hundred hours. The motion would be all wrong. ha ha ha

  15. keith66
    Joined: Sep 2007
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    keith66 Senior Member

    I have two inline sanders made by Chicago pneumatic & Desoutter both are good for fairing small boats. The trick is to use a light guide coat of black acrylic from a spray can , just dust it over the area to be faired & when you knock the high spots down the black shows up the lows. Other fearsome tool we used to use was a square plywood pad mounted on a polisher, got a bit exciting if you went into an upstand.
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