Recomendation epoxy

[Karnic]

I need to epoxy a piece of coosa board to my transom any idea which works best in order to obtain a very strong adhesion. Also I would like to coat / paint the board with epoxy how is it done? Ideas please.

 

[john_morris_uk]

I usually use West System Epoxy but others are available. I’m not sure if any are particularly better or worse.

The adhesion will depend on how well prepared the surface is. If it’s keyed up with some grit paper and degreased it should be fine. The official West System advice is to wet out both surfaces and then use a thickened epoxy mix to stick the items together. This ensures that if the surface isn’t completely flat, voids are filled with epoxy and you get a strong joint.

To coat the panel, pour a bit of epoxy on and use a flexible plastic scraper to spread it around. You’ll need at least two coats. Light sand and wash in between to remove the amine blush. I use cheap paint brushes with the bristles cut off to a couple or cm’s or less to paint epoxy on edges and tricky areas. Long bristles are a pain when painting thick gloopy epoxy. Throw the brush away once used. Don’t bother trying to clean it.

Measure proportions carefully. (Put cling film on a digital kitchen scales if you haven’t got metered pumps for the base and catalyst)

West catalyst is water soluble but you’ll need acetone for the base or mixed epoxy if you need to clean up anywhere base or unhardened epoxy has got onto.

Use protective gloves!

 

[john_morris_uk]

PS Best results are when the temperature is within limits!

PPS Big mixes of epoxy generate heat and go into thermal runaway. Small mixes or put it in a tray so it’s got a large surface area.

PPPS Paper or plastic cups are good for small mixes.

 

[Poignard]

You'll probably find all the help you need in the various manuals published by WEST Epoxy:

https://www.westsystem.com/app/uploads/2023/09/WS-User-Manual-2020.pdf

https://www.westsystem.com/app/uploads/2022/10/Fiberglass-Manual-2015.pdf

https://www.westsystem.com.au/wp-content/uploads/2019/07/wooden_boat_restoration_and_repair.pdf

 

[Hacker]

To add to John’s reply. West system is good and you can get small packs of the appropriate materials. You will need either latex gloves or marigolds (people do become allergic to resin). After keying the surfaces, then clean with acetone. Use a paper/plastic cup to make up a mix of sufficient size to do the work. The surfaces to be bonded will need wetting out with one coat of resin and then thicken the mixture that is left to add the thickener (if the surfaces to be bonded are relatively flat then thicken to mayonnaise). If you apply to the wet first coat then no need to sand. Apply and put pressure on the surfaces to ensure they stay in contact (you should get squeeze out), use weights/clamps as appropriate. Remember to clean up whilst still wet, otherwise you will have fun later!

 

[john_morris_uk]

To add to John’s reply. West system is good and you can get small packs of the appropriate materials. You will need either latex gloves or marigolds (people do become allergic to resin). After keying the surfaces, then clean with acetone. Use a paper/plastic cup to make up a mix of sufficient size to do the work. The surfaces to be bonded will need wetting out with one coat of resin and then thicken the mixture that is left to add the thickener (if the surfaces to be bonded are relatively flat then thicken to mayonnaise). If you apply to the wet first coat then no need to sand. Apply and put pressure on the surfaces to ensure they stay in contact (you should get squeeze out), use weights/clamps as appropriate. Remember to clean up whilst still wet, otherwise you will have fun later!

I think I forgot to explicitly explain that you wet both surfaces and then add a layer of thickened epoxy while the wetting out layer is still ‘wet’.

I’d mask off the edges and clean up with acetone, although a fillet of thickened epoxy left round the edge wouldn’t go amiss.

 

[Mr Googler]

This chap does great videos. There’s more videos on the Cossa transom job later on

 

[Plum]

I need to epoxy a piece of coosa board to my transom any idea which works best in order to obtain a very strong adhesion. Also I would like to coat / paint the board with epoxy how is it done? Ideas please.

I do not know what coosa board is but regarding coating/painting the outside face, the top coats should not be epoxy which has very poor UV resistance. Top coats should be a good UV resistant paint or varnish, preferable a two-pot for the longest life.

 

[john_morris_uk]

I do not know what coosa board is but regarding coating/painting the outside face, the top coats should not be epoxy which has very poor UV resistance. Top coats should be a good UV resistant paint or varnish, preferable a two-pot for the longest life.

That’s good advice. I’d forgotten to point out that epoxy degrades in UV and needs a coat of paint or UV resistant varnish.

 

[Karnic]

Thanks all for your kind help and ideas. John morris I read your recommendations word by word. Thanks. Pad ( coosa board ) is going to be epoxied and attached underwater in order to mount tranducer and underwaterlights to board in order to eliminate need to make holes in transom.

 

[davidej]

I was in a Sainsburys where they were doing wine tasting. Punters were offered smal amounts of different wine in those clear plastic egg cups sized containers calibrated in ml.

I cleared their waste bin and now have a lifetime supply to accurately mix the small batches of epoxy that I use.

 

[Karnic]

Transom was treated with gelshield. Will i sand away all gelshield in order to epoxy pad for permanent adhesion or Will I just sand a bit and apply epoxy resin to board and attach to transom?

 

[Karnic]

I usually use West System Epoxy but others are available. I’m not sure if any are particularly better or worse.

The adhesion will depend on how well prepared the surface is. If it’s keyed up with some grit paper and degreased it should be fine. The official West System advice is to wet out both surfaces and then use a thickened epoxy mix to stick the items together. This ensures that if the surface isn’t completely flat, voids are filled with epoxy and you get a strong joint.

To coat the panel, pour a bit of epoxy on and use a flexible plastic scraper to spread it around. You’ll need at least two coats. Light sand and wash in between to remove the amine blush. I use cheap paint brushes with the bristles cut off to a couple or cm’s or less to paint epoxy on edges and tricky areas. Long bristles are a pain when painting thick gloopy epoxy. Throw the brush away once used. Don’t bother trying to clean it.

Measure proportions carefully. (Put cling film on a digital kitchen scales if you haven’t got metered pumps for the base and catalyst)

West catalyst is water soluble but you’ll need acetone for the base or mixed epoxy if you need to clean up anywhere base or unhardened epoxy has got onto.

Use protective gloves!

Thanks mate. Yes im going for the west system was recommended to use the 404 high density filler. Transom was coated with gelshield should i remove it all or light sand the grlshield and attach board

 

[john_morris_uk]

Thanks mate. Yes im going for the west system was recommended to use the 404 high density filler. Transom was coated with gelshield should i remove it all or light sand the grlshield and attach board

I imagine a light sanding to provide a key will be fine. If the area is usually underwater you’ll need to clean and degrease thoroughly.

All IMHO.

 

[Karnic]

I imagine a light sanding to provide a key will be fine. If the area is usually underwater you’ll need to clean and degrease thoroughly.

All IMHO.

Yes Area will be underwater. Even I imagine that a light sanding, clean and attach transom pad will be fine. Gelshield ( International)is for osmosis and coat is very sound , flat no flakes and no bumps. I assume in my humble opinion that it would do the Job.