Fairing compounds?

Hi all,

The plywood dinghy I'm building is close to the painting stage, I still have to fair and sand the hull (amongst other things). The thing is I'm running low on epoxy and want to know if there are any good alternatives that aren't too expensive.

Does standard automotive "bog" stick to wood? Primed? With what primer?

I've been using west system epoxy and have a bag 410 fairing filler thickener. I could probably use the 410 in a cheaper epoxy as it is cosmetic rather than structural, but which one?

Something I can click and collect in Melbourne would be a bonus.

Thanks, I appreciate your help.

Would very strongly suggest you don't use automotive "bog" as it will surely be a polyester formulation and in general terms this doesn't adhere to epoxy well. Epoxyworks.com have done trials adhering polyester gelcoat over West epoxy and suggest it can be done but surely in your case it is absolutely best to stick with an epoxy based filler. Whitworths Melb have International HT9000 250ml epoxy resin and ~80ml hardener for about $50 (have used this extensively) and this would probably be compatible with 410 but would suggest you call them on Call 1-800-251-431 to confirm - but I would just buy the smallest quantity of West resin and hardener and use it with your 410 - they have many agents in Melbourne.

www.westsystem.com.au/find-a-dealer/

Norglass do a Norsystem epoxy resin 1l kit for ~$60 which is excellent - I am using it now - check with the tech advice line if 410 will be compatible I expect it will be. If not they have the Norcells light filler.

www.norglass.com.au/find-a-stockist?postcode=3000

As far as I remember shrinkage of polyester and epoxy fillers is different. Septone polyester fillers are great for decks and topsides of grp boats and the lightweight one is easy to sand. The fibre filled one is obviously harder and stronger. But they are intended for grp boats not wooden boats.

I have nothing to do with any of the above 4 companies.

Mike, by the sounds of things you've done the hard yards, stick with what you're using your familiar with it and know it should bond to your substrate. I use Q cells for easy sanding type of work, but I must admit I seldom get that fussy. Car bog/ builders bog will work in a pinch but it will haunt you later.

On my fishing vessel I regularly used body filler to repair any scars on the Oregon planked topsides. Sometimes the surface was coated with paving paint, sometimes bare then over painted with paving paint. Body filler like fibreglass is porous and needs paint. On a dinghy that's not on the water 24 hours a day body filler is fine. Just make sure the filler you use is easier to sand than the hull substrate.