thinning epoxy

[ben goodfellow 1]

hi all , whats the best stuff for thinning epoxy down to glass wings and the like thanks.

[WolstonFlyer]

Have you looked at using a coating resin such as this.

NOTE: I have never glassed a plane but have been looking at options.

***Link***

[Steve Hargreaves - Moderator]

Hi Ben...you need laminating epoxy.....that's already thin!!!

Try here & here...

[Ben B]

Laminating resin is pretty thin. If you heat it it flows even better but cures faster. Personally never felt the need though.

[crispin church]

use clear varnish

[Bucksboy]

I use the Bucks Composites stuff, its excellant. It doesn't need thinning, its already washing up liquid consistancy. Read the 'how to glass' guides, it really is that simple.

nothing to do with bucks Composites either.

[cymaz]

On the two part epoxy I have used meths spirit before but it takes a long time to go off. Even when I've finished the rest of the bottle it's still soft.

[John Olsen 1]

Have a look at what the West system people have to say about it:

**LINK**

It seems that you would be best to find an epoxy that is formulated for the purpose with the viscosity you want rather than thinning it yourself.

I've used lots of the West system stuff on a boat that I am building, over 100 litres of it.

John

[SDF]

We had a demo at the club I used to belong to of how to glass a wing but can't remember who it was by now.

Use laminating epoxy as already advised. Thin this as required using pure methanol. Lay the glass cloth over the wing. Don't try to use a brush. Pour the epoxy sparingly onto the cloth/wing and then use a camel hair paint roller cut down to about 2" wide to spread the epoxy. Gives really good results with just the right amount of epoxy to properly wet the cloth without excessive weight gain. Pop the roller in a jam jar of acetone before the epoxy sets and it can be reused.

[TheFlyingCrust]

There's a discussion elsewhere on the site re this. Ronseal Floor varnish - the hi spec one - seems to do the trick. And its water based. Not tried it myself but intend to when I get round to building again.

Ian

[Former Member]

[This posting has been removed]

[Bucksboy]

I use the cheapest foam 2-3" wide foam rollers i can find and then throw them away.

[jrman]

Use Isopropyl Alcohol. You can get it from your friendly chemists.

[Danny Fenton]

People are mentioning laminating resin, be careful because laminating resin will dry with a waxy finish this is deliberate apparently and is to allow the next lamination to adhere easily. This is a pain to sand through.

My advice would be to stick to resins such as Phil Clark's LS285 finishing resin or the West systems 105 resin, both I have used to great effect and do not need thinning.

Cheers

Danny

[jrman]

The "wax" is used as a means of reducing the emission of volatile vapours as the resin cures. It does not assist in the bonding of subsequent coats, in fact it does quite the opposite and should be removed before applying any further resin. An easy way of doing this is with "wet & dry" paper using IPA (isopropyl alcohol) as the wetting medium. You'll know if you haven't done it well enough as you will get "fish eyes" in the subsequent coats. Don't confuse Laminating Resins and Finishing Resins, they are both prepared for different purposes.I have found that excess thinning ( >25%) will reduce the effectiveness of most finishing resin systems.

[StarLoc FiveStar Adhesives]

There is no wax added to ANY epoxy resins , the wax is only added to the styrene diluted polyester resins not the type of resins used for skinning wings

In epoxys the `greasy` surface with some hardeners is due to some reacting with moisure or co2 in the air as the resin sets, alcohols such as meths, methanol or IPA  used as thinners for epoxy can increase water absorbtion and help to cause the greasy surface

In polyester resins the parafin wax is added to resins used for top coats that are exposed to air, the wax floats to the surface and gives a barrier to prevent air inhibition and give a surface cure, the resin with wax in is used for top surface only, the polyester resin with no wax us used for formulating gel coat ( with pigment ) and lower laminations to give a strong bond between layers that the top surface wax would prevent

In some resins such as polyester the wax has an additional benefit of cutting voc emmision giving greater open time and less smell but is usualy only added as an air barrier ,

In reactive methacrylate coatings and adhesives based on volitile esters such as methyl methacrylate we add certain waxes to the formulation to give longer open time, less smell and a tack free surface

But in epoxys there is almost never any reason to add a wax to the formula so its almost never added

Edited By StarLoc FiveStar Adhesives on 20/05/2013 19:38:33

[ben goodfellow 1]

lots to have a look through there . i have got the lend of some zap finishing resin . going to have a go with that , 5 star i was browsing your shop , do you do any finishing resin , i couldnt find it on the site my friend uses floor varnish but my opinion it was really brittle i was not that keen on the stuff.

[StarLoc FiveStar Adhesives]

Posted by ben goodfellow 1 on 20/05/2013 20:00:12:

5 star i was browsing your shop , do you do any finishing resin , i couldnt find it on the site

We do make an epoxy finishing resin , but it is out of stock for a couple of weeks while we make some more, its actually been manufactured but we need to do routine QC checks on the batch to check things like stability etc before its back in stock