My Pacer has a leak :( I need to repeair the crack between two pieces of wood where the tape/epoxy has failed. So I think it's a matter of strip the paint and the dead tape off, then put epoxy in, then tape, then paint over the top.
Now I don't have a clue what I'm doing, but the good part is this dinghy is so cheap that I can't make it (much) worse than it already is...
What kind of epoxy should I be using? I'm looking at
www.theboatwarehouse.com.au/categories/boat-building-maintenance/epoxy-resins-hardeners-glues-fillers.html
and I'm baffled.
Can anyone suggest what I should be using to do this repair?
Thanks!
Plenty of good videos and manuals available.
Buy your epoxy resin from your local business. Just make sure it's epoxy and not fibreglass resin. Avoid boutique epoxy and for ease of use, use one that's 5:1 by weight. Use digital kitchen scales to measure. Use fibreglass tape and wet it out with the epoxy. Your Pacer was probably built with Fibreglass resin over fibreglass tape. Never put fibreglass resin over plywood.
Your link also shows polyester resin. Don't use that for repairs, use epoxy.
Norglass or West system are good. I use BoteCote which is also very good. See the boatcraft.com.au link above. I wouldn't use the fast hardener although fine for cooler temps, will go off too fast if using in summer.
Thanks for your help!
What is "glue strength filler"? Do you mean epoxy mixed so it's not very runny? Or some other product?
How much epoxy does one use in a repair? I realise that's a "how long is a piece of string" question, but I see the stuff comes in quantities from 200ml or so to several litres. I have to repair a crack that is around 10cm long, obviously going well beyond that length in all directions to make sure the repair is strong. I was looking at this product, which claims to be flexible, which I think is a good thing given the location of the crack. This "kit" has 250ml in total, would that be likely to be enough?
www.theboatwarehouse.com.au/boat-building-maintenance/epoxy-resins-hardeners-glues-fillers/west-system-g-flex-650-epoxy-kit-250ml/
(obviously can buy more, but the stuff isn't cheap, ...)
If I was choosing an epoxy with fast/slow hardner options (the Norglass have those), what would best suit repairs done in about 20-25 degrees C?
Epoxy must always be mixed in the resin and hardener ratio according to the manufacturer - Norglass and HT9000 are 3:1. The glue strength filler is a separate product to the epoxy resin and hardener.
See Internationals HT120 glue blend filler to use with their HT9000 epoxy resin. Might be easiest to get the 250ml resin and 84ml slow hardener and smallest bag of HT120. That should be enough for your 10cm and a bit more. No need to go "well beyond....." If its a 10cm crack and thats all just 2cm further each end and wide enough for the tape you are going to use. The HT9000 system also has a more lightweight and easier sanding fairing filler.
www.international-yachtpaint.com/en/au/boat-paint-products/fillers-and-epoxy/epiglass-ht120-glue-blend
www.whitworths.com.au/250ml-ht9000-3-1-res
That G/flex is gold plated not sure why, wouldn't use it.
Norglass sell their epoxy resin in a 1L kit and have Norcells as their lightweight filler - it is not clear if their other filler Microtalc is a glue strength filler or heavier still easier sanding filler - suspect the latter you can call them to check they are very helpful. The have Norfill as their glue strength filler.
For what you need a little bit goes a long way, like most things the more you buy the cheaper it gets, I like to use 2:1 because even a dill like me can't get mixed up. Glass tape 50mm wide is universally handy. For fillets and glue I would recommend cabosil ( fumed silica ) you can keep adding it till it stands up like mum's pavlova. And it won't hurt to have a bit extra because when you start using it you will undoubtedly find other uses for it. Here's a handy who's who of fillers
Select to expand quoter13 said..
Epoxy must always be mixed in the resin and hardener ratio according to the manufacturer - Norglass and HT9000 are 3:1. The glue strength filler is a separate product to the epoxy resin and hardener.
See Internationals HT120 glue blend filler to use with their HT9000 epoxy resin. Might be easiest to get the 250ml resin and 84ml slow hardener and smallest bag of HT120. That should be enough for your 10cm and a bit more. No need to go "well beyond....." If its a 10cm crack and thats all just 2cm further each end and wide enough for the tape you are going to use. The HT9000 system also has a more lightweight and easier sanding fairing filler.
This is incredibly helpful. The variety of products out there is very confusing to the novice. I can get to Whitworths in Melbourne to get the HT brand epoxy resin, fillter and hardener.
What is the difference in the physical behaviour of epoxy without glue filler and epoxy with the filler? I'm imagining that with the filler it behaves more like "builders bog", is that right? Does it glue things more strongly?
Ok good to be of help, thanks. The International HT9000 system at WW Melb sounds like your path of least resistance.
The epoxy resin without the glue filler is for applying epoxy sealing coat/s to bare timber hence greatly increasing the waterproofing of the surface of the timber, also giving it more durability and hardness. Also as a sheathing resin for wetting out fibreglass tapes and cloths - the lightest cloth being dynel which is commonly used as an overall surface cover of hard chine (and cold moulded) timber boats.
www.whitworths.com.au/dynel-cloth-104g-per-metre
Adding the glue strength filler to the resin makes the mix into an epoxy glue which will have the required strength and also gap filling characteristics for glued timber joints. It glues joints better and more strongly than just the resin alone due to its extra gap filling properties than the liquid resin mix. Epoxy resin alone has suitable strength for sheathing using cloth and tapes but it is not a glue with gap filling properties.
This is a dated guide but has good information - note the HT9000 is now a 3:1 mix. Not sure why it is not available on the International site but it could be there somewhere.
docplayer.net/65726966-Epiglass-multipurpose-epoxy-resin-guide.html
Epoxy by itself is reasonably strong but if thick then will probably crack without reinforcement.
Your repair will probably be fine with just the resin and fiberglass reinforcing.
If you want to glue two pieces of wood together with gap filling capability, best to use a high strength filler for the strongest joint.
If you want to make a fillet to join and strengthen a perpendicular joint, use a medium strength filler. (example between stringer and plank)
If after using the fiberglass and resin you want to make the surface fair and smooth, use a light weight filler (micro spheres etc) that is easy to sand to the surface you want.
Different fillers for different purpose. Too many to list, the above list by woko gives a pretty good overview, but read the product description for what you are going to buy for the detail.
if the dingy is cheap, get the epoxy, hardener, cloth, acetone, a couple of cheap brushes and a mixing cup.
Clean down with acetone after sanding, then apply unthickened epoxy to wet out.
If you need to thicken up, or make fillets to aid the cloth laying down, just use talcum powder.
If you buy everything listed, your cheap dingy wont end up being that.
Sanded properly, and a few good layers, she'll be right to go.
