Model Boat Mayhem
Mess Deck: General Section => Beginners start here...! => Topic started by: andymart on June 25, 2015, 06:40:24 pm
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Building a balsa hulled boat and noticed a thread about using tissue and dope and not being strong enough for everyday use. It mentioned fibreglass tissue and epoxy.
Is this the sort of stuff? or too thin? http://www.hobbyking.co.uk/hobbyking/store/__10905__Glass_Fiber_Cloth_450x1000mm_18g_m2_Super_Thin_.html
Secondly is PolyC ok for boats? I see mention of another product called Ezecoat both seem to be water based. I have an allergy to some epoxies and why I mention these. Can anyone tell me if these dry to a hard finish that can be rubbed down then painted on with acrylic sprays?
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My very simply answers to your questions:
Yes it is.
No it isn't thick enough - certainly not for a balsa hull. You could use two layers of it but that's tedious and expensive.
PolyC? Never used it but it sounds and looks very much like.......
EzeCoat, which is what you say it is and does what you say it does. I have used it and it is quick, easy and not messy.
On the whole I prefer 1oz glass cloth and Z-Poxy Finishing Resin to anything else.
Other opinions are available................... 8)
DM
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I used a hand sand epoxy and fiberglass mesh on my wooden boat 20 min working time let it sit over night and sanded smooth filled small blemishes and painted with wood primer latex turned out very well.
Rick
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may I make a quick comment with regard to using tissue covered with dope and soforth, not being strong enough for everyday use. I am surprised my owld mucker didn't pick this one up - owld man Dave ya nar from ACTion - as well as the rest of us has also built models and covered with them with tissue and dope and the models have been around and in regular use for years with no ill effects. Have a look at some of Glyn Guest's builds, this is his favourite method of covering Balsa Hulls.
If you have a look at the Swordsman build - for beginners - in the Masterclass - we did the tissue build there and Mr nice man Dave did a write up about the procedure of covering using tissue, dope etc.
aye
john
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Hi one and all the problem I face is actually getting hold of dope, sanding sealer and tissue both cost wise and logistically. I am from old school and can remember covering control line planes with firstly silk and dope then moving to nylon and dope. Still have a couple built in 1970s that although covered in dust could still fly and finish would be ok. If I price up including postage glass cloth 2 metres and 500ml of Polyc it comes to £23 for similar amounts of dope, sanding sealer, thinners, and tissue you are looking at best part of £40. I am sure you can appreciate why I am asking. Don't really want to go down epoxy route due to sensitivity.
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Andymart
As an old school modeler, why dont you use nylon stockings or tights, applied with Eazycote or Epoxy finish. PLEASE ask the missus first, she might still be wearing them!!!!!
Slide the leg part over your boat hull pull the creases out then paint on the finnish, 2 layers are bomb proof
Mark
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I am surprised my owld mucker didn't pick this one up - owld man Dave ya nar from ACTion - as well as the rest of us has also built models and covered with them with tissue and dope and the models have been around and in regular use for years with no ill effects. If you have a look at the Swordsman build - for beginners - in the Masterclass - we did the tissue build there and Mr nice man Dave did a write up about the procedure of covering using tissue, dope etc.
aye
john
Tha's reet there, m'duck, but Swordsman is plywood and not balsa. Anyroad up, them clever b*ggers from Z-Poxy have made their poxy so easy to slop on and sand dahn that it dis'na make any sense to use smellylose nah.
Things move on, marra - even me!
Dave M
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Mark
Thanks for that, I did see reference to this on another posting. I might just give this a try, cant wait to ask her indoors for some stockings or tights {-)
Andy
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Rather informative answer to this question in current Model Boats Design Special magazine in the article on Twinkler. Also an alternative offered in the July 2015 ( ie current "normal" edition) of Model Boats in the Beachbaby build article. Both mags worth buying
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Hi thanks for that I do have the special edition and noted the comments made, that given choice again he would use glass and epoxy. I am assuming the other article is about stockings and ezecoat or tissue and dope? Unfortunately I live in a very outlying area so not easy to get these mags unless I drive into major towns some 15 miles away. Yes I could get a subscription and have had these in the past but found about only 5 magazines in a year had interest articles for me. The local newsagent does not stock any magazines like this, and won't specially order in either as wholesalers are a nightmare.
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Hi Andy,
As you surmise, the Beachbaby article advocates two layers of 15 denier stocking material applied with Eze Cote. I know the problems that you can encounter with lack of shops when living in a rural area. I live in a major town which actually has a pretty abysmal range of shops for its size. The one thing that it DOES have is a good old fashioned model shop. It has been run by the same family since I was a kid (I am now retired) and I am very lucky as they seem to be a thing of the past now
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Strangely we did have a model shop in local town until around 5 years when the owner retired. It sounds exactly like yours had all the latest gear catered for all disciplines of the hobby but also had all the widgets etc. that you could not get elsewhere. I moved from Epsom area and was spoilt for choice their as had Mick Charles Models on my doorstep plus quite a few smaller model shops all within 30 minutes away. Most model shops near my location don't stock anything to do with boats and concentrate on Aircraft, Trains or Cars. The nearest would be Westbourne Models however have not had good experience with them in the past, plus they are 90 mins by car away.
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Fibreglass and PolyC will work to give a suitable finish, It is not so hard as epoxy so more easily damaged. One possible problem with a balsa hull is PolyC is water based so will cause the surface of the balsa to swell. It might be best to give it a coat of PolyC before laying the glass allowing you to sand the surface back again.
Jim
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Hi Andymart
Regards asking for old stockings or tights, my missus thought i had a fetish. Maybe she was right?????? but my daughter and her mates all supply me now, got some in stock so ok for a year or two
Mark
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Jarvo....we would only worry if you started wearing the pink fish net variety {-) .......with matching pink sequined smoking jacket.... :kiss: ......Derek
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Has anyone tried cloth/stockings and polyurethane varnish as the varnish seems to dry hard?
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Has anyone tried cloth/stockings and polyurethane varnish as the varnish seems to dry hard?
In the past, I used ordinary cotton bandage (as per first aid kit) with both polyurethane varnish or with resin on the internals of wooden built boats ( mostly the old Aerokits range). While I preferred using poly as it was both cheaper and less messy, I think that the resin had the edge. Like the originator of the question, I get a reaction from f/g cloth so I try and avoid it. I have tried gloves and barrier cream but still suffer a reaction so try and avoid anything to do with fibre glass
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Check out the sheet nylon here. http://www.rcworld.co.uk/acatalog/Fibre-Glass-Cloth-Tissue-Nylon.html (http://www.rcworld.co.uk/acatalog/Fibre-Glass-Cloth-Tissue-Nylon.html)
Us owd-fashioned types used to cover model aeroplanes with this stuff, using shrinking dope. Once the material is tight and you've filled the weave it will accept any paint finish you like. I'd say it's almost as tough as glass-cloth and resin on sheet balsa and ply structures. There are several "how to do it" videos on You Tube.
DM
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Derek Warner
There is nothong wrong with my pink fishnets, but there is more resin than support!!!!!!
Mark
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My allergy is epoxy and to some extent cyano used them both for years never a problem. Barrier cream and gloves make no difference.
On aircraft I used to use bandage from first day kit (not crepe) and PVA to join wings and to be honest it seemed to be just as strong as epoxy. However doubt if it would be any good as a base for paint
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If you are allergic to epoxy then Eze Cote is a good water based substitute - dries quickly too.
I am OK with epoxy but cyano gets me every time although I can manage with the odourless version.
Colin
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I'm going to give ezecoat/Polyc and the stockings a go. One last question I have not glued in propshaft yet, should I do this prior to covering/painting?
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Hi Andy
Seel the hull, stocking epoxy etc, fit the propshaft then finish and paint the hull, that way the shaft wont get in the way of the stocking but you wont ruin you hull finish when you fit the prop tube
Mark
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Dare I ask where I put the black seam? {-)
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In seriousness guys thanks. I have tried the stockings on some scrap wood just to try out, I used polyurethane varnish (not water based) first to seal let that dry sand very lightly to remove any nibs then stretched the stockings over then apply another coat of varnish, let that dry rubbed edges off and gave another coat, let dry rubbed down and then stretched stocking over again and followed process with about 4 coats of varnish, actually the finish is quite good. I am going to try the eZecoat/polyc however took the lid off a bottle of eZecoat in the shop and it smells exactly the same as Wickes clear water based varnish, I wouldn't be surprised if it isn't exactly same product or very close.
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Hi Andy
This might seen daft but i usually put the seam domn the port side chine!!!! I seem to hit the landing stage on that side!!!! As you have done tests using varnish, test the Wickes stuff the same way. Water based varnish come from somewere, posibly the company that makes Wickes also bottles Ezycote of Deluxe. Who knows???
Let me know what the result is. Wickes is a hell of a lot cheaper than Ezicote
Regards
Mark
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I know its an old thread but.
PolyC is Ronseal XL Floorseal, its sold only in industrial quantities to the trade, and is 100% developed to not only seal wood, but also to harden the fibers in wood and to protect it.
The biggest use is on gymnasium floors and some shopping malls also have wooden floored areas where it is used.
PolyC should NEVER be applied to balsa or thin (<1/32") ply without priming it first as being water based it will warp.
How do I know this, I wrote the article in Model World that brought this alternative to epxoy coating to the model flying community :-X
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I am a newbie building my first boat ,balsa skinned with ply. Having built planes and used tissue I decided to use this instead:
Fibreglass Surface Tissue 30gsm used with fibreglass - moulds - resin
£2.95 for a sq-mtr and I plan to use basic fibre glass resin and hardener £9.99 for 500ml. all from E-bay
If I still need a finer topcoat I'll try Eze-coat or something similar as suggested here
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Graham
What do you prime the wood with?
Thanks
Andy
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In regards to the Wickes varnish, well to be perfectly honest I cant tell the difference between this and polyc. Both dry in similar time and both seems to have same hardness, that said though I also experimented with thinned pva and also thinned aliphatic glue both of which gave a harder but I suspect more brittle finish. None of them however come close to epoxy though which seems hard but resilient. The only trouble is I cant work with epoxy or cyano :((
Graham pointed out that you need to prime the balsa, I noticed on youtube that polyc recommend you coat the balsa with a coat of polyc, let it dry and sand then cloth and polyc. Tried this with all products used so used wickes varnish as a primer followed by wickes varnish and cloth, so on so forth.
One thing I didn't try was sanding sealer, cloth and dope. But recall back in the day covering flying wing control line models with nylon and dope, this was a good finish and hardwearing, however shrinkage can be a problem. As stated originally cost and actually buying dope, nylon, thinners and sanding sealer is cost prohibitive and difficult in our area to get, most shops wont send by post either.
I have asked Graham to clarify what to prime wood with.
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cellulose sanding sealer was the best solution that didnt warp wood when I was testing polyc
FYI I asked Ronseal when I was first testing their product (I only found out due to their chemical engineer also being a modeler, and had done some work on gliders using it) what if any end user alternatives were available and they insisted each product is engineered to do a specific job.
If it helps here is some info I did for Rcworld
(http://i314.photobucket.com/albums/ll431/grahamdrry/pc1_zpshudccfek.png)(http://i314.photobucket.com/albums/ll431/grahamdrry/pc2_zpskkinyrw3.png)(http://i314.photobucket.com/albums/ll431/grahamdrry/pc3_zpsedwysyc1.png)
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Thanks Graham, however which takes me back full circle that I cant get cellulose dope to make sanding sealer (which is talc and dope for those who don't know) or sanding sealer, without paying exorbitant prices for shipping let alone the product.
I am sure you can appreciate that some people here will experiment with all sorts of products, personally I cant use epoxy or cyano and also have a reaction to some paints. I spoke to some member at my club yesterday, and in regards to painting balsa models some don't even bother with tissue, or fibreglass etc. they simply rub down paint with primer rubbing down then undercoat and enamels and their boats seem to last. Not sure I still go down this route though.
For those that want epoxy and fibreglass matting, non modelling place to get it much cheaper is http://www.easycomposites.co.uk/
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I got mine from here > http://www.ebay.co.uk/itm/Bolgers-Cellulose-Sanding-Sealer-High-Build-Fast-Drying-Primer-For-Woodturning-/121700670960?var=&hash=item1c55ecddf0 (http://www.ebay.co.uk/itm/Bolgers-Cellulose-Sanding-Sealer-High-Build-Fast-Drying-Primer-For-Woodturning-/121700670960?var=&hash=item1c55ecddf0)
£4.99 250ml + £2.50 p&p
Remember I was looking for a fast less nasty alternative to Epoxy (GF) covering aircraft that would be just as strong as epoxy when finished, but with the advantage of being non harmful and washes off in water. For a boat hull I would go for Polyc and heavy grade tissue. Applied neat on ply, but to a sealed surface first, like Balsa. Its really down to how the balsa (or very thin ply) is supported inside the hull, if the formers also have stringers then the balsa shouldnt be able to warp, unlike an open aircraft wing that is just wing ribs and 1/32" balsa sheeting.
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Thanks for link, however costs again are starting to mount up. I would have to buy the sanding sealer then thinners to clean brushes. I have tried polyurethane varnish (oil based) as a sealer and then using this with fibreglass and it seems to be as good as other methods and probably the cheapest overall. I tend to use acrylic paint and am assuming acrylic will adhere to polyurethane varnish?
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Andy
Buying cellulose thinners in modelling quantities is madness. Get a 5L can of Standard Thinners from your local motor car paint suppliers; it'll cost about 1/10th as much and lasts you ages. It's fine for thinning sanding sealer and dope and used as a general thinners and brush-cleaner. "Gun Wash" is even cheaper, I'm told.
DM
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now that's interesting, good tip just had a look 5 litre of nitro cellulose thinner at £10.99 at local motor factors. Also have just found cellulose sanding sealer 1 litre for £10.95. So don't understand why dope is so expensive is it not used by other industries? I know fireworks are manufactured using dope for instance but there are not many of them around where I can just go there and buy.
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Hi Andy
Dont go to a motor factors look on line for car paint suppliers. Much cheaper again.
For sanding sealer, Try adding talc to the poly c, try it on a scrap piece of wood and leave to dry, should work!!!!
Mark
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Thanks Mark
Trouble is I am in the middle of no where and very thin on the ground for car paint suppliers without driving 15 to 20 miles, but we do have a car factor close by.
I have tried a similar method to what you are describing for sanding sealer, I don't think it matters what medium you use as the talc is for filling the grain as long as the medium dries. I tend to find water based products never seem to dry that hard and seem to have a sort of very slightly rubbery feel to them. You can see what I mean if you use water based varnish, and then use a solvent based version, one never seems to be hard the other dries to a hard finish, the other thing I have noticed is water based products are permeable which allows the wood to move as doors in my house where this has been used swell up during colder months yet doors where solvent based was used don't move.
Anyway thanks one and all for your input, it is appreciated. I will buy some PolyC along with other products, as I do have various models to finish.
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As a perfectly usable substitute for sanding sealer for wood I use car laquer apply 3 coats quick de nib of the wood and then 3 and rb down and prime with high build primer....it will seal and cover all the grain
Dave