Epoxy Resin Questions

[pjl83]

Hi guys.

Is there much difference in makes/brands of epoxy resin? The "west" system seems to be the most common but what do you guys think?

Basically I need around 5 litres of resin plus hardener, 200grams of glue powder and 100grams of low density filler. I have searched through the web but there are so many sites all varying hugely in price that I am not sure as to the differences between them.

I have a guy at work on the case to see what he can get me at trade price, but if this doesn't work out then I'll be ordering my own so any suggestions or help and advice would be greatfully recieved.

Thankyou in advance! ;)
Paul

[Mike]

In short, Paul, the answer is yes in that there is a lot of difference between the various brands of epoxy resins available. Personally, I have only ever used West System. It is perhaps dearer than the rest but it is definitely reliable and does what it says on the box. The cheapest West resin prices I have found are here (http://www.cfsnet.co.uk/acatalog/CFS_Catalogue__West_Multi_Purpose_Resin_329.html) but I would not buy the glass tape or fibreglass from that supplier as they are too heavy for what you are building. There is a thread I started on this subject here (http://www.backyardboatbuilding.org.uk/forums/showthread.php?t=91). And there is an even better thread on it in an entirely different forum here (http://www.backyardboatbuilding.org.uk/forums/showthread.php?t=112&page=4) (note, the link is to page 4 of the thread as that is where it becomes most relevant to your inquiry - the rest of the thread is interesting but wanders all over the place).

Note the references to resorcinol glues and, in particular, the alternative resins suggested by our friend, Andrew E, who is a man of considerable and wide boatbuilding knowledge. I intend to check out Andrew's suggestions before building our live aboard cruiser. On resorcinol, it is particularly useful if you have any allergy to epoxy but you do need to ensure your joints are close fitting if you go that route. For a first timer, epoxy resin is probably your best bet. It will handle a multitude of sins and is stronger than you would imagine.

Hope that helps in some small way, Paul.

Best wishes

[pjl83]

Thanks Mike. I will try to stick to the west system as you suggest as there will undoubtabley be a multitude of sin that requires covering lol.

I must check with the site though that they will deliver to the Isle of Wight, as some online companies that use private courier firms wont always do so. Royal mail see no difference however. Even when I've oredered stuff before from a site that states "UK Delivery" I've had the argument where I've had to remind them that the island is infact in the UK and they disagree lol, so I always suggest that they change there wording to "Mainland UK" which doesn't always go down well.

Is there anyway of knowing how a litre converts to a kilogram. Maybe somebody has a tin and could see if the bottle states the 2 measurements so we can convert. I'm guessing it's quite a heavy substance looking at the pictures and the weight stated.

Thanks for the info Mike,
Paul

[Andrew L]

Thats answered one of my first questions to you guys - thanks for that! We too suffer from the 'not part of the UK' type problem even though we are connected by two of the most historic bridges in the UK and a major Euro route goes across the Island. Changing our postal address from Isle of Anglesey to Gywnedd usualy solves the problem! Even the wife's contact lenses couldn't be delivered!

[pjl83]

haha. not just us on the Ilse of Wight then, lol

The only thing puzzling me now is knowing what litres equate to in weight of epoxy. I've emailed a couple of suppliers to see if they can help.

This is a great site for learning, I'd be lost without it ;)

[Mike]

Paul, I think you said you need 5 litres. If you buy the 6Kg pack, that should be enough. Just remember to take it easy when you are using the stuff until you get used to it. You will also need the measuring pumps or some means of being able to measure the ratios accurately (West is a 5:1 resin/hardener mix).

Also bear in mind that there are two hardeners, one for low temperatures (down to 5 Celcius) and the other for higher temps (15 degrees and above). These also have different pot lives. You will increase pot life considerably if, once you have thoroughly mixed it, you then pour it into a much wider/shallower container. That is down to the fact that the tighter the container, the greater the mix produces its own heat and the sooner it becomes unworkable. When you first start using this stuff, you tend to waste a lot, especially if you don't know about extending its pot life. Make sure you have plenty of mixing cups and spatulas available before you start, and its best to take precautions against skin sensitivity by using disposable gloves. You can get all this paraphernalia from any West System supplier.

If you have any further questions on using epoxy, I will try to help from my own knowledge. I do have the big 'bible' of epoxy use as published by the Gougeon Brothers (title: The Gougeon Brothers on Boat Building). As the makers of West System as well as boatbuilders in their own right, there ain't much you can't find in their huge book. It is no problem for me to look up what you need as and when required.

I have looked up estimates in the 'bible' and it tells us this: for interlaminate glue joints, you will get about 13 square feet per pound weight of mix or about 2.7 square metres per kilogram of mix. You would estimate by calculating the approximate number of square feet or square metres of boat surface area and dividing it by the appropriate number. It does not speak to litres. It also suggests you allow for a 20% wastage (scrape off or sanding down).

Note: you will not be laminating. Those estimating parameters are for laminating ONLY. There are other figures for 'coating' and for build up. Again, not relevant to your purpose unless you intend to coat the entire outer hull surface with epoxy. You need to use it primarily for gluing and for laying in tapes where needed to strengthen joints, particularly at each plank joint. John's estimate of 5 litres is not entirely helpful in this regard. Note that gluing, as opposed to saturation or buildup when 'coating', requires the use of additives.

Most use West's 403 microfibres or 404 High-Density. Others will prefer 405 Filleting Blend. A good general use adhesive filler is West's 406 Colloidal Silica, ideal for general bonding and filleting. What you choose will be to some extent dependent on how much you want to spend versus how strong and durable you want the boat to be.

Some folk prefer to add wood dust instead of expensive proprietary blenders. I think the key there is to ensure that the wood dust is consistent in size (dust, not little lumps) and a decent match in colour to what you are gluing. I have even read of some people using things like a chalk dust or baking powder to thicken the mix for gluing but I haven't dared to try that for myself yet. I tend to stick (pardon the pun) to West System's product advice. I am not an experimenter with such things.

Best wishes

[Mike]

Errumm ... the above post was not intended to end the thread guys. Nor was it a definitive statement.

Has nobody else got anything to say on this topic? Surely not! Loads of you have used epoxy so how about posting a few words of advice for someone who is new to the process.

Come on. I am getting a bit fed up with those who just sit back and wait until they receive an email alert about posts before they think about making a contribution.

If you enjoy logging in to this site then how about making a contribution to its content instead of just being a browser or a recipient of alerts? Paul's thread is precisely the kind of thing we are supposed to be sharing with each other. He deserves more of a response than just that from me above, surely?

Some time ago, a member advised me that he believed I should stop responding to others first and instead allow members to inter-react between themselves. I felt it was valid comment and have since tried very hard to do that. However, unless more of you take up the task then it is down to me alone. So, please start contributing a few words here and there. Otherwise, I might as well just save myself all the time and trouble and shut the site down. Remember the motto: "Use it or lose it!"

Regards

[Mike]

Thats answered one of my first questions to you guys - thanks for that! We too suffer from the 'not part of the UK' type problem even though we are connected by two of the most historic bridges in the UK and a major Euro route goes across the Island. Changing our postal address from Isle of Anglesey to Gywnedd usualy solves the problem! Even the wife's contact lenses couldn't be delivered!That is outrageous, Andrew! Tell you what, mate, if you encounter that problem again then let me know and you can use my address. I will then immediately send the purchase on to you by Royal Mail. That oughta get around the rip-off merchants.

I must say that, after nine years flying outside of the country, my return in 1998 was quite a shock in experiencing the rip-off Britain it has become. Anything that deprives the rip-off merchants of their unfair gains is 'really kewl' by me.

Best wishes

[George Waite]

Mike
Fullers Earth or Bentonite is another possible filler powder for epoxy resins.
George

[Clip]

I usually use cabusil, (thickener) and wood flour for pastes, but where abrasion is possible I have added silica flume (extremely fine silica). This is creates a very hard material which does not sand well. Bentonite never heard of using that?

That is an expansion clay (with water), again very fine. I have thought of using bentonite/tar strips to seal some types joins where I didn't want glue, but a compression joint. I have used this material underground when creating water tight concrete/rock joints. If water comes in contact with it it expands and seals. The tar makes it sticky and flexible.

[Mike]

George and Peter

I am truly grateful for this input. It is totally new to me and led me to do some research on the products you describe. Very interesting indeed. And they all seem fairly inexpensive when compared to some of the West System fillers. Very good stuff, I imagine.

Needless to say, my rather well educated wife, Jeannette, chimed in and announced she knew of these products as used in the beauty therapy industry. Jeannette never ceases to amaze me with the breadth of her knowledge in so many things. She's an environmental management type and we can talk for hours on that subject, which is quite dear to our hearts.

That said, I think I would stick to West System products as I have found them very reliable in the past, producing results as stated in the literature. It is, of course, the rather expensive way to go but I am a great believer in the old adage that one should not spoil something for the lack of 'a halfpenny worth of tar'.

You two guys are extremely well qualified and undoubtedly know what you are on about but I am not qualified in the engineering field so tend to be a bit gutless and rely on manufacturers' recommendations. I kinda like the principle of using wood flour (or dust) as a filler since I am gluing wood. It seems logical to chuck some into the resin mix to thicken for bonding woods together.

Thanks again for responding to my post in this helpful way. It gives me great encouragement with respect to this little website, which has gone rather too quiet just lately. I imagine the recession is distracting a lot of people from their boatbuilding dreams. It is, thankfully, not bothering me and my plans one little bit, though its impact on others around me has slowed me down somewhat.

It's a bit of a topsy-turvy world out there at present, with the usual greedy practices starting to creep back in (bankers and employers in particular!). Frankly, I think we should have let the bankers boil in their own oil rather than bailing 'em out. They really are among the world's most ruthless and uncompassionate people I have ever come across. So too are some employers. But that's another subject.

Kindest regards

[bowdidgemarinedesigns]

Is there much difference in makes/brands of epoxy resin? The "west" system seems to be the most common but what do you guys think?



Interesting question and one that I asked many years ago of a chemical engineer.
At the time we had two epoxy resins on and ..FGI and West System.
To cut a long story short, he took both away for testing and on returning 4 days later gave us the results and history.
Turns out, many years ago there were only 3 factorys worldwide that produced epoxy resins and hardeners. The resin was the same, but in regards to the hardeners, there were 60 variations. Now West System owned 204 and 206 and Fgi bought the hardeners adjacent. The difference between the two products was 99.5%
Later, FGI bought the rights to produce their own here in Australia and NZ and added further additives so that on mixing the product would turn blue intially to show that the resin/ hardener was properly mixed. On curing it turned back to clear again.
The difference is price ??
FGI Epoxy resins are half the price. West.. your paying for the name.
Because FGI also produce polyester resins/ vinylester etc etc for all the commercial and large boatbuilding industry requirements, so therefore they can afford to spread the costs around.

Another thing that came out was:
5:1 ratio mixes produce a less elastic cured bond than say a 2:1 ratio blend. However, for fairing the boat prior to painting, a 5:1 ratio epoxy is far superior than a 2:1 or 3:1 mix as these lower ratio's tend to clag your sandpaper and the end result is nowhere near as smooth of a finish as then 5:1 ratio's

Just a comment
have fun
regards
Mark
www.bowdidgemarinedesigns.com (http://www.bowdidgemarinedesigns.com)

[Philip]

well after messing with a new laptop l wanted to add to this. there are other brands of epoxy BUT the biggest difference l have found is west system goes alot further. epoxys like C P EPOXY like treacle so although cheaper less coverage. l had the same problem finding a good supplier without high p@p! l have found a supplier in romsey uk whose prices are unbeatable but l must add l picked it up so no p@p anyway a 6kg west system pack was 79 pound the number is 01285 740404 hope this helps regards phil

[Mike]

Before buying my last 'C' Pack (30 kgs) of West System, I searched high and low for the best price I could find. Robbins Timber list it at around £352 + VAT.

I found CFS offering the best price at around £235.00 + VAT so had made up my mind to buy it from there. However, when I went in to order my plywood, Andy Vowles of Robbins offered me the epoxy at trade price, which was £248.86 + VAT. He also offered all the other West stuff at a similar discount.

Now, CFS charge for delivery and they also add a surcharge for dangerous goods, which brings their price up. Robbins deliver using their own fleet of trucks, so no surcharge. And for reasonably local deliveries of a quantity of product, they don't charge for delivery. They have not charged me to deliver. Naturally, the farther away you live and the smaller the quantity of product, the charge increases a little.

Frankly, Jeannette and I decided to stick with Robbins Timber to supply us, mainly because they have always given us good prices and first class service. Andy bends over backwards to be helpful and to offer good advice. Thus, even if Robbins was a bit dearer than CFS, I would not easily switch suppliers. I think it actually pays to show some customer loyalty, especially when times are hard. Support the good guys is one of my mottos. If you do then you are likely to find they support you when you need 'em to.

Naturally, if it was going to cost us £100.00 more, then it would be time to look elsewhere. But for just a few quid here and there, we figure it's worth that for the good service and guidance we get.

Just my two penneth. I would add that any member who has trouble getting hold of materials at a reasonable price should let me know and I will do what I can to help them.

Best wishes

[Peter Radclyffe]

arent sp resins still on the i o w

[Mike]

No idea, Peter. SP resin is still on sale here but I don't know where the company is based. Perhaps other members will be able to advise you.