Model Boat Mayhem
Technical, Techniques, Hints, and Tips => Wood Care: => Topic started by: Gazzalene on April 25, 2019, 07:06:15 pm
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I am new to building and at the bit where the plan says to seal/waterproof while assessable .
I am using balsa and ply.
When epoxy is mentioned,i think of Araldite.
Can anyone give advice on what I should be doing inside the hull and outside?
On plan says to epoxy the hull the other epoxy with light glass cloth.
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Inside the hull a couple of coats of sanding sealer will do the trick unless you are expecting a lot of water! the exterior can be done the same way with added tissue but for a 'proper' job I recommend z-poxy (or similar) and glass tissue.
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I have z-poly bought for another reason some time ago.
its came in a box with 2 bottles,i have used this as a glue! its fairly thick,would seem too thick to paint on.
Do you thin this stuff down?
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I find with zpoxy, that it seems quite thick, but once you start spreading it with a brush it seems to go a long way, a single mixing pot was enough to do my 40" hull with some to spare (on the outside at least) if you have a lot of internal structures, that might use a bit more getting it into all the nooks and crannies.
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There are different types of Z Poxy. Glues with various setting times and finishing resin. It's the last you should use for covering a hull. Use the wrong type and it will be like covering it with syrup which has gone rock hard.....
Colin
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that explains it- it is the finishing resin I used.
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Yeah,and the stuff I have is not.will get the finishing type.
I suppose the label will say how to use BUT read a thread which said not to use much hardner as it "plasticises" the wood?
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When using epoxy always mix in the proportions in the instructions. Epoxy does not really use a "hardener" as it is a two part resin where the parts combine to form the actual epoxy resin. If you do not use the correct proportions then it will not cure properly, it might remain sticky or go soft.I doubt there is a risk of it "plasticising" the wood, normally this needs it to be soaked in quite concentrated ammonia.
Jim
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Why, not just look it up? https://www.zapglue.com/epoxy-resins (https://www.zapglue.com/epoxy-resins)
And yes, just use in accordance with the instructions it comes with, you are unlikely to go wrong then. It's also a good idea to do a trial on a test piece to familiarise yourself with applying it and how it brushes out etc.
Colin
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I use Z-POXY finishing resin inside and fiber cloth and finishing resin outside with good results my best advice is to let the boat sit for at least 24 hours before trying to sand and clean the surface when sanding is complete the boat can be painted very well I do use a base coat of primer and then a finish colour .
Rick
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A number of questions arise out of this:
1. Is laminating epoxy the same as finishing epoxy? If not what is the difference?
2. Working on the "longer it takes to harden the better the joint" theory can you just add filler/ micro balloons to finishing epoxy to make a good and slow drying thicker gluing construction epoxy.
3. Is Z Poxy recommended because it is what is sold in model shops or because it is better than other manufacturers?
I ask because being a simple sort of guy & only having used fibreglass hulls & built model aircraft I have only used standard 60min epoxy which following West System advise I have never thinned.
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Tug, Your point about "what the shop has"
Been to the model shop for Z Poly finisher. Shop said "don't want that" "cant beat this", PolyC
Only stock poly C so got that, label says its for using with glass cloth and finishing surface.
Also water soluable/based? so no smell I presume.
Also got tin of sanding sealer! guy said it reeks but excellent for balsa and inclosed part of hull.
Too late now I have bought it!
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......................Been to the model shop for Z Poly finisher. Shop said "don't want that" "cant beat this", PolyC.................
That is a water based polyurethane about which I know nothing. My questions about epoxy still stand.
I hope that it goes well for you.
I understand the bit about what the model shop has. Around here we have a lot more boat builders, full size hull manufacturers & chandlers than we have model shops.
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I am in London,my nearest LHS is 21miles away. Got a Hobbycraft 10miles away but its not great for this kind of stuff.
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Poly C is a similar prodct to DeLuxe Eze-Kote but apparently cheaper.
It is fine as a a finishing resin and has the advantages of low odour, water cleanup and dries quickly. It is not as tough as epoxy but should be perfectly adequate for most model boating purposes. A lot of people use it.
Colin
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I don't recommend many sellers but here's one that I do if you want resin
https://www.bucks-composites.com
They know their stuff; its not been sat on the shelf for 12 months and they even sell a colour dye for resin should you need it
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For what it's worth your local model shop 99% of the time will say what they have on the shelf is the best. Same for most stores really. Just don't forget, the BEST way to do things is to try them on scrap material first. Practice first and make your mind up, after you've tried a few times, but I would always advocate supporting your local shop first if that's what they have. I'm not familiar with what LHS have though, but they seem to be mentioned more these days.
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The best way to do things is to develop an undertstanding of the issues involved so that you can make your own informed decisions.
The information is readily available on forums such as this one and on many other websites that can be easily found from a Google search.
Unfortunately too many people are unwilling to put the effort in and are looking for quick answers which might not in fact resolve their questions as their particular circumstances have not been fully explained and people start making assumptions which may be incorrect and bad advice is given as a result with unfortunate consequences.
As always, what you get out of these things is proportionate to what you put in. There is no substitute for doing some homework in terms of reading up on relevant matters either by trawling through the information already posted on websites such as this or by reading the many books available on the subject which are intended to give readers a general grounding on all the basics.
As in anything else worth doing, there are no quick fixes if you want to enjoy the hobby. Gaining a basic understanding of the subject is all part of the fun and satisfaction. Enjoy!
Colin
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hi there
if you have a look at the build (in the Masterclass section) for the 63 ft RAF Launch - skip the build parts and stuff like that - and half way down you will see the write up about using ZEpoxy resins on the hull. This may give you some guidance in what you are going to do. In the text of the build where I have used polyester resin for the inside of the hull, you could quite easily use finishing ZEpoxy resin as I have done on many occasions. As has been mentioned previously it is worth while reading up on various methods; increases your confidence in doing it. As has also been mentioned, with while practising on a bit of scrap wood first - cos I can tell you I have the TShirt and its really heartbreaking having to scrape a hull back to get rid of the mush which is left when the resin doesn't go off.
john
https://www.modelboatmayhem.co.uk/forum/index.php/topic,9758.msg90492.html#msg90492
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Exactly what colin said.