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Forum topic by Oldschoolguy posted 01-16-2020 04:48 PM 310 views 0 times favorited 9 replies Add to Favorites Watch
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Oldschoolguy

108 posts in 473 days


01-16-2020 04:48 PM

Hi y’all, I recently posted a question on this forum titled “Finishing”. I was questioning how to finish and fill gaps in a hard maple cookie. The cookie will be used as an end table type for the wife. You can view the photos I posted for the topic in the Finishing section. I was gifted some filler and thickener from a very gracious member. Now I’m ready to purchase the expoxy/hardener for filling the voids of this project. I read much about West Systems products and purchasing the epoxy from them. What would y’all recommend and what websites to buy from. Links, suggestions, tips, and any other help is forever appreciated. Thanks.


9 replies so far

View SMP's profile

SMP

1779 posts in 542 days


#1 posted 01-16-2020 04:55 PM

I just buy whatever is cheapest at the big box store or wally world. Bondo, Evercoat etc. Its all the same stuff.

View John Smith's profile

John Smith

2193 posts in 799 days


#2 posted 01-16-2020 05:06 PM

Floyd – for a novice in the epoxy world, West System can be an expensive investment.
the epoxy itself is expensive. then you have to buy their proprietary 5:1 pumps.
I get my epoxy from RAKA Epoxies which is here in South Florida.
they have epoxy that is easily mixed 1:1 or 1:2 ratios which is much easier and less expensive
for the beginner. this is just one option to consider – there are dozens and dozens of epoxies used
in the woodworking world – and everyone has their favorite.
there is a phone number on their website if you wanted to talk to a technician to discuss
your project with them.
looking forward to following your journey in this project.

.

.

-- Failure is proof that you at least tried ~ now, go do it again, and again, until you get it right --

View Oldschoolguy's profile

Oldschoolguy

108 posts in 473 days


#3 posted 01-16-2020 05:16 PM

Thanks John, Since my wife is dead set on finishing the top in epoxy, how much do you think I’d need for the top. The legs are of soft maple, therefore, what would you recommend for a finish?

View CaptainKlutz's profile

CaptainKlutz

2438 posts in 2131 days


#4 posted 01-16-2020 06:11 PM

1) Cost?
Epoxy is expensive, and there is no way to avoid spending ~$80-120 per gallon (or more). Buying smaller quart quantities is much more expensive per ounce (~3-4x). Since epoxy has 3-5 year shelf life with proper indoor storage, buying the gallon kits usually works for me for several projects? Beware of shipping costs. Some require hazmat labeling/packaging; which can double cost for online purchases.

2) What to get?
Another challenge is not all epoxies are same. There are different formulations optimized for different applications. Usually the hardener controls the cure rate, but there are differences in resin blends between brands. If you want an adhesive, then existentially they act the same. But if you want thick section casting, or hard coating for large surface; you need to pick one carefully. The key challenge with epoxy is the exotherm as it cures. The thicker the cross section; the more heat it holds and the faster it cures. Casting epoxy for thick sections is always a very slow cure to avoid thermal run away. Large surface coatings tend to be very slow, or they specify the max recommended mix amount per batch to reduce self heating. All epoxies should list the max recommended cross section (or batch size) in a single pour somewhere in the spec sheets to help you pick one best suited for your application.
When in doubt, test it yourself. Nothing worse than mixing up a quart of 8 hour slow cure epoxy and it starts
smoking in mix jar during mixing, until the cup melts and catches fire. (true story).
Generally speaking, unless your shop is cold place; the best epoxies for wood working are slowest curing versions. I keep both 5 and 15 minute cure hobby epoxy on hand for quick repairs, but most time use slowest cure available. Especially in the heat of Arizona summer.

3) Where?
Due high shipping costs, I find almost same price buying small amounts of epoxy adhesives locally as online? About the only time I buy epoxy online is when I need more than 2 gallons, or I need a special thick section casting epoxy not stocked locally. Buying local also solves the problem where you run out, and need more quickly. Hazmat shipping is always via ground and seems to take forever.

West Marine is a national chain in most major cities that carries West System epoxies, and occasionally puts it on sale. The boat industry is large user base for West Systems, and the online marina suppliers tend be cheapest.
System Three is sold by Woodcraft and others, it works just as well and I recommend it.
Both are top notch epoxy adhesives with a long successful history.
My local industrial finish supplier sells a private label table top coating epoxy that works well, and is sold for commercial bar counter top finishing.

Hope this helps.

PS – Been working with adhesives/polymers professionally for over 30 years, with several adhesive patents; and I am still an idiot compared to others. There are volumes of books written on epoxy types, and they teach graduate degrees on the topic. So it is impossible to fully comprehend epoxy in a forum post. Keep reading every thing you can.
YMMV

-- I'm an engineer not a woodworker, but I can randomly find useful tools and furniture inside a pile of lumber!

View John Smith's profile

John Smith

2193 posts in 799 days


#5 posted 01-16-2020 07:14 PM

Floyd – a one quart kit would be more than enough to cover your 20” slab.
one quart would be the total volume of Part-A and Part-B of whatever brand you get.
example: if you got a qt. kit of a resin that is a 2:1 ratio, you would get two different sized
bottles that would make up the total volume of one quart when combined.
2:1 ratio would be like two ounces of resin and one ounce hardener = 3 ounces total.
properly mixed: two parts resin, one part hardener, you should not have any left over
when the two bottles are used up.
(as for the table legs, use whatever you normally use with your other wood projects).

-- Failure is proof that you at least tried ~ now, go do it again, and again, until you get it right --

View bmerrill's profile

bmerrill

82 posts in 710 days


#6 posted 01-16-2020 08:03 PM

Have had great success with Total Boat Epoxy products.
I do use the specific pumps to mix at the correct ratio, but I also weigh the product which dispensing just in case I “short” stroke the pump. Usually make batches of 8oz or less.

-- "Do. Or do not. There is no try". Yoda

View hkmiller's profile

hkmiller

200 posts in 718 days


#7 posted 01-17-2020 12:57 PM



Floyd – for a novice in the epoxy world, West System can be an expensive investment.
the epoxy itself is expensive. then you have to buy their proprietary 5:1 pumps.
I get my epoxy from RAKA Epoxies which is here in South Florida.
they have epoxy that is easily mixed 1:1 or 1:2 ratios which is much easier and less expensive
for the beginner. this is just one option to consider – there are dozens and dozens of epoxies used
in the woodworking world – and everyone has their favorite.
there is a phone number on their website if you wanted to talk to a technician to discuss
your project with them.
looking forward to following your journey in this project.

.

.

- John Smith

John, Good link to RAKA. I live in Tallahassee, and due to the humidity, would you use the non-blushing hardner?

-- always something

View Blindhog's profile

Blindhog

149 posts in 1685 days


#8 posted 01-17-2020 02:21 PM

A local mill (Berdoll Sawmill) recommended TAP Plastics EX-74. I’ve used this for filling cracks/voids in mesquite (and other woods) for tabletops and other uses. Simple mixing (1/1) and ease of application has made this a good choice for my work. First gallon lasted for two years and was still in good shape to the end of the bottle. Note: it was stored in a conditioned space.
Dries clear and can be easily colored.

EX-74

-- Don't let perfection get in the way of plenty good enough

View John Smith's profile

John Smith

2193 posts in 799 days


#9 posted 01-17-2020 04:53 PM

I was just explaining something to Floyd about epoxy.
there are literally hundreds to choose from for different applications
in different parts of the world in different climatic conditions. (it is mind boggling).
“blush” is where the epoxy oxidizes and causes a haze to form on the surface.
so if you do not intend to coat the project with a clear varnish, poly or paint,
and you want the epoxy to be the show finish, such as a table top, non-blush
additives are necessary. just tell your supplier your project and ask for guidance.
West System has doubled in price since the last time I bought it. I use epoxy
strictly for bonding – never table tops or filling voids in slabs. so this new fad
of making slab river tables, etc. is a new world for me. I am learning just like
you guys. I muddle through all the hoopla and try to absorb the most “accurate” info.
if I make anything for a boat that has to have an epoxy coating, I top coat clear it
with a good quality marine spar varnish to keep it from hazing or deteriorating
from the UV and weathering.
my next project is making wooden slat seats for my small boat out of cypress and
they will be coated with epoxy and several coats of marine spar over it.
just make sure you go by the directions on the label precisely to avoid potentially
messing up your project really bad.
also a good idea is to ask your supplier if mixing the parts by volume or weight
will give the best results. some types go strictly by volume only. others go strictly
by weight only. most don’t matter. just something to consider when ordering
your epoxy.

Edit: the above information on EX-74 posted by Blindhog is an excellent tutorial
of how to use epoxy. well worth the read.

.

.

-- Failure is proof that you at least tried ~ now, go do it again, and again, until you get it right --

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