Fiberglass fairing

Would anybody have advice on fairing compounds?
I plan to fair interior fiberglass that is not smooth before painting. I think about using west system 410 as a fairing filler but was wondering if there is any cheaper alternative? I saw 3M glass bubbles in bulk for a fraction of the price and wonder how it compare?

Any advice welcome.

L

Mixing your own fairing compound stinks as most folks do not waiting long enough and end up with an epoxy rich mix that is really hard and time consuming to fair.

Long ago epoxy and micro balloons was the norm , don't bother!

Far easier to use one of the paint companies pre mixed fairing compound and an electric jitterbug or manual long board to get the surface as you want it.

The use of electric , not air for the tools keeps the oil needed in the air tools from getting on the surface.

I've used fiberglass reinforced bondo with good success in the past. It bonds well to polyester resin, cures quickly, and is easy to sand.

You can look at the TotalBoat line. They tend to be a lot less expensive than West Systems sold at West Marine and have a good reputation.

Full disclosure: I almost always use West Systems, because I can walk right into the store and get it. They have both fairing compounds and glass microballoon fillers (among others) to work with epoxy, as well as their own line of epoxy, etc:

-- https://www.totalboat.com/

I have not use the Totalboat fairing compound but BoatWorks Today uses them and says they work very well. I usually just mix my own with West. I have about 4 or 5 different fillers and use one of them depending on what I am doing.

I checked TotalBoat TotalFair but the product is hardly available in Canada. I only found it on Amazon.ca at a ridiculous price.
I saw that SystemThree have a similar product named QuickFair.

I am trying to find the easiest to sand. It is above water and only to prep for a smooth painting.

L

I started using epoxy a long time ago, so was a die hard "mix my own" fan (that's just how you did it back then). I still am for general use. BUT, I decided to try some of the pre-made fairing compound a couple of years ago and I'm a complete convert. It is as creamy as perfect frosting. Nary a lump or pinhole to be seen. Basically fairing bliss.

I used System Three's version at that time, but I would think any of the big marine players' similar products would be as good.

(So this comes in two buckets and you mix them together at the given ratio, but it's already "fairing compound" and you don't add your own microballoons or etc.)

On a separate note, if you do mix your own, and if you are thinking to use WEST Microlight, read the fine print to see if it applies to you. IIRC it's not to be used anyplace that gets hot (decks) and I think also perhaps you cannot put certain paints over it. Don't take this as gospel but just as a note to check into the details.

Frosty

If going with epoxy Systems3 Quickfair is what I use. I have tried a number of others and mixed my own but the Quickfair works so good that is all I use now.

I have used a number of fairing compounds extensively. 410 is basically overpriced micro bubbles. These should cost about $10 / pound, west system's price of $20 for 2 ounces is crazy. Try: https://www.aircraftspruce.com/pages/cm/fillers/bubbles.php

The more micro bubbles you put in your epoxy, the easier it is to sand. You want to put them in until it holds it's shape easily and does not flow at all. You can make it quite 'dry' until it's too dry to spread well so you have to find that sweet spot. It's challenging to use because getting a consistently hard product is difficult so you'll have various densities all over the place as you mix batches, and you can't mix too much or you risk it hardening in your cup. For small areas where a single batch can fill it's a reasonable solution. Pinholes can be an issue depending on your mix and application process.

As for some of the others mentioned. Total Fair is a two part paste mixed in a 1:1 ratio with blue and yellow components that mix to make green. It's quite thick and difficult to spread thinly about like peanut butter. For thicker fills it works well, for filling smaller issues it's challenging. It sands well and is consistent to work with and does not form pin holes easily.

The best one I have used, and my preferred choice for most jobs is System Three Silvertip Quik Fair. It's a two part epoxy filler paste that is mixed in a 2:1 ratio It's consistency when mixed is that of softened butter, it holds its shape well and it has a creamy texture that spreads very nicely. It's easy to sand and does not form pin holes easily. It works well for fine imperfections and small depth fills and trowels on easily enough you can use an 8-10" wide drywall knife for application. If you need to make a lot of thick fills it's not the best at that because of it's creamy texture.

I consistently use all three depending on the job. For small, single issues where I'm already mixing epoxy, I'll throw some micro into some of the epoxy. Otherwise I reach for the system 3, unless it's a deeper fill then I'll get the quik fair out, although I won't order more of it once I've run out and stay with the System 3 and micro as my two systems of choice.

Used TotalBoat TotalFair and liked it....

But as Jay said a good polyester or in my opinion vinyester "bondo" is good enough for many jobs.

Thank you guys for your input, very much appreciated!
I will give a try at system 3 quickfair. A 1.5 gal kit will cost about 200$ (Canadian) and I should have enough for the surface I want to fair and paint in the boat.
TotalFair is difficult to get up here.
Mixing my own would cost me more (about 120$ for a gallon of epoxy plus 60 for the hardener plus the same for microbubble) and will take more time.
Hopefully I will be able to get the baby skin surface I aim to get and the result will be nice.
Will post the result when done!

L

I use this stuff a ton. (Cheap and quick delivery)

Perfect for fairing if mixed right. (As other have mentioned, you need to mix with resin, let it absorb for at least an hour, then add hardener when you go to use.). I will leave it to soak overnight if i can.

Ive mixed it 50/50 for deck texture. But that was early in the season and it was a bit cold out. You need to adjust your mix for your environment.

sbman said:

The best one I have used, and my preferred choice for most jobs is System Three Silvertip Quik Fair. It's a two part epoxy filler paste that is mixed in a 2:1 ratio It's consistency when mixed is that of softened butter, it holds its shape well and it has a creamy texture that spreads very nicely. It's easy to sand and does not form pin holes easily.

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That's the one I used after years of rolling my own. Super impressed. If not doing a massive job it lasts a long time.

I have heard good things about Awlfair as well.

psneeld said:

Used TotalBoat TotalFair and liked it....

But as Jay said a good polyester or in my opinion vinyester "bondo" is good enough for many jobs.

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Actually some of the "pros" use what's called "bondo lite" which is a very lightweight bondo fairing compound. I used it when I re glassed my Mainship flybridge on recommendations from Legnos boat works out of Groton, Ct.

jleonard said:

Actually some of the "pros" use what's called "bondo lite" which is a very lightweight bondo fairing compound. I used it when I re glassed my Mainship flybridge on recommendations from Legnos boat works out of Groton, Ct.

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Thanks, good tip.

I use the microlight. Easy to mix, easy to apply, easy to sand. Cost is not a major factor as I am not a boat builder or fiberglass repair person. Another advantage is the slight tan color of the West system makes it a lot easier to see and sand the small ding repairs. I have used a cheaper brand that was pure white. It was just as easy to work with but difficult to see so I went back to microlight.

SoWhat said:

I use the microlight. Easy to mix, easy to apply, easy to sand.

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I do see that the OP specified this for interior work, so not at all saying Microlight is not appropriate for that. But in case others are reading along, I wanted to add that WEST System 410 Microlight has some "no go" situations. Namely:

Not recommended under dark paint or other surfaces subject to high temperatures. Cures to a tan color.

Probably the OP's boat is not subjected to high interior temps so it's a fine recommendation for him; but I know I'll often read a thread when I have a variation on the theme of the OP and it's one of those "fine print" items that might not otherwise be obvious. I've seen people use it on decks and that would concern me. Even up north, a sunny afternoon on a horizontal surface can be quite hot.

I really like this stuff:

Interfill 833 Fast Cure Boat Filler | Interlux

Easy to apply, doesn't sag in vertical surfaces, easy to sand and great finish.

I use a lot of West System's epoxies and their various fillers but I have not managed to keep them from sagging on vertical surfaces.

jleonard said:

Actually some of the "pros" use what's called "bondo lite" which is a very lightweight bondo fairing compound. I used it when I re glassed my Mainship flybridge on recommendations from Legnos boat works out of Groton, Ct.

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I have found that the pros always prefer faster products. They know what they are doing, have skill and practice on their side. They just get in there and get it done, and don't want to wait on the product.

For myself as an amateur, I find that the slow products are more cost effective (even if they are more expensive and/or slower) and produce a better result for me. With little experience or practice, working quickly before a batch of something goes off (filler, resin, paint, etc...) is not a good thing. It takes up more time as I end up having to sand more, redo more and the results aren't as good as I feel rushed during the application process and make mistakes or do poor work.

System Three Quik Fair is a good compromise on speed, it's one of the faster epoxy fillers and in warm temperatures you can get two fills on the same section in one day, it's ready to sand in about 4 hours if the temps are warm. The others I've used usually need 8-12 hours.

What paint are you planning to put on top of it?

Unless ventilation is excellent, I'd not use polyester compounds (like Bondo) in an enclosed space on a big job. Epoxy compounds still require ventilation but won't kill you. Epoxy sticks 10X better too.


I like the epoxy from US Composites and their fairing powder is top notch too and sands easily. Much less expensive than West.

sbman said:

I have found that the pros always prefer faster products. They know what they are doing, have skill and practice on their side. They just get in there and get it done, and don't want to wait on the product.



For myself as an amateur, I find that the slow products are more cost effective (even if they are more expensive and/or slower) and produce a better result for me. With little experience or practice, working quickly before a batch of something goes off (filler, resin, paint, etc...) is not a good thing. It takes up more time as I end up having to sand more, redo more and the results aren't as good as I feel rushed during the application process and make mistakes or do poor work.



System Three Quik Fair is a good compromise on speed, it's one of the faster epoxy fillers and in warm temperatures you can get two fills on the same section in one day, it's ready to sand in about 4 hours if the temps are warm. The others I've used usually need 8-12 hours.



What paint are you planning to put on top of it?

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I ordered a 1.5gallon of quick fair.
I plan to use Interlux prekote primer and Interlux Brightside off white paint.
I used brightside on some fiberglassed bench top and it has a nice looking finish and is very tough, everything I am looking for [emoji846]

But before I get there I need to clean and get rid of this $%&##$! carpet glue!

L

Lou_tribal said:

I ordered a 1.5gallon of quick fair.
I plan to use Interlux prekote primer and Interlux Brightside off white paint.
I used brightside on some fiberglassed bench top and it has a nice looking finish and is very tough, everything I am looking for [emoji846]

But before I get there I need to clean and get rid of this $%&##$! carpet glue!

L

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You will get a really nice gloss finish with that combination, and it is hard wearing so I'm sure you'll be happy with it.