R

ron sterba

Well Known Member
Iam doing my tail feathers (9A) fiberglass tips. Ive purchased the 105 resin and 205 hardner and 410 & 403 as well as the extras per my buddy instructions.. Ones a filler and ones a adhesive. Do you favor one over the other say on the elevator tips and the horizontal tips. What kind of cloth lbs or weave do you prefer? Iam going to sand off more of the gelcoat because of the different qualities in the make up of the glass and gelco because as the UV rays take its toll on the gelco you have spider cracks like I see on my air intake on the 172/skyhawk over time. What # is micro ballons. It does not mention BALLOONS on the cartons of 403 & 410. Do you know of a builders site that gets into the nitty gritty of this glass thing.

Thanks RON
 
You have just discovered one of the drawbacks to the West "System", far as I am concerned that is.

They seem to be trying to keep away from using the typical verbiage of the fiberglass world, and instead use their own terms/code numbers.

Look here for a better idea of what they have, or preferably, just go to Spruce, and order a pound each of mirco, flox, and cabosil.

Here is my fiberglass "mini-guide"

Micro is only for filling-----no structural qualities. Easy to sand

Flox is structural, use where strength is needed. Hard to sand

Cabosil is a thickening agent, makes the epoxy stay where you put it, instead of running off. Can be used with micro, or flox. A little goes a long way......

Good luck,
 
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What Mike said... I've used a fair amount of their 404 "structural filler" though, and have done some comparisons with flox. I prefer the former. Flox makes a pretty rough surface, and the cured material is hard to sand. Annoying on visible surfaces. 404 behaves much more nicely. Just as hard to sand, but the initial surface is much nicer looking. On the other hand, flox is a lot cheaper.
 
Everything West System sells (with the exception of flox - WS Structural filler) is a blend of their own design.

I finally gave up on their fillers and started ordering fillers (balloons, flox, and cab-o-sil) directly from Aircraft Spruce. With those 3 fillers you can create your own blends and get just the right filler for just the right application - no guessing.

I still use West System epoxy though.
 
I would not use the West System for anything other than fill and finish (which it is excellent for). There are much better resins available that have superior structural qualities more suited to aircraft building than West, which was developed for wood working and boat building.
 
9GT said:
I would not use the West System for anything other than fill and finish (which it is excellent for). There are much better resins available that have superior structural qualities more suited to aircraft building than West, which was developed for wood working and boat building.
Click to expand...

Such as? Could you give us some examples, please?
 
9GT said:
I would not use the West System for anything other than fill and finish (which it is excellent for). There are much better resins available that have superior structural qualities more suited to aircraft building than West, which was developed for wood working and boat building.
Click to expand...

I have used West for the complete structural adhesive (and glass finish) on the wood wings of my Hiperbipe, as well as for composite layups on everything else I've done. I find the stuff excellent. Test coupons show incredible "bite" on wood and great laminating strength on glass. Many people use West for primary structure on their glass aircraft, so I'm wondering what your experience has been that leads you away from their product. Is it something specific, or simply a preference for something else?
 
BSwayze said:
Such as? Could you give us some examples, please?
Click to expand...

Burt Rutan had done extensive testing on various composite resins, epoxies, hardeners, and glass weaves. In the plans for the Cozy MKIV, the West System was specifically named as an "non-approved" epoxy for construction of his composite designed aircraft, along with a list of approved epoxies,,,,so I imagine it did not pass his testing procedures for structural strength and it was recommended the West System be used for finishing only. You will notice the difference's in properties in working with West in comparison to what I use for any structural lay-ups, MGS, which is an FAA approved epoxy system for certified aircraft parts. Costs are pretty much a wash so why would anyone not want to use the best product available? http://www.aircraftspruce.com/catalog/cmpages/mgsresin.php
 
West Systems works fine

For our purposes on the RV series West Systems works great. I use 410 for most of the fill needs.

If you are interested in attaching and blending the glass parts on the tail, here's what I do.

Do not dimple the skins!!!!

Fit the glass piece where desired. You may have to sand some off the lip of joggle so it doesn't hit the tip rib. Drill and cleco.

Fill the end cap (stabilizer) with foam. Epoxy in place with a few dabs of epoxy being careful not to bond to stabilizer. For this I use 5 minute epoxy and 410 to speed the process. Remove from the stab and make a fillet of epoxy and 410 on the inside of the glass where the foam meets. Sand flush when cured.

When you are ready to permanently bond the glass piece, drill with #30 and cleco.

Scuff the metal at least one inch on top and on the underside. Sand the gel coat with heavy grit paper where it will bond with the metal.

Use CS4-4's. Because the head is very thin on these you can counter sink the skin. Test fit each rivet for flush fit.

When ready to attach permanently, clean with acetone. Mix a batch of thick West Systems and 410. Liberally apply to the glass joggle. Cleco the piece in place and begin riveting with the 4-4's. After all rivets are in, use an old credit card, hotel room key card etc... to spread the epoxy and make the seam smooth.

When cured, block sand to get relatively even.

More later. Gotta go to work.
 
You might look into the MGS epoxy's from Aircraft Spruce. They're much more suited to hand wetting out than West is (its a viscosity issue). Many of the composite builders prefer MGS over anything else.

Other alternate choices: Aeropoxy and EZpoxy.

As for West Systems, I've used it for years and its OK. Use the slow hardener if you want more than about 45 minutes of working time.
 
Has anyone used their G-Flex, I used it on all my tips, works great and you can actualy bend it when cured, thinking of no cracks after paint.
 
This is just a copy of an old canard builders news letter, please note paragraph 5:

Newsletter# 47 October, 1994

Epoxy resin systems can be tailor-made for any specific application. For composite aircraft construction, using the wet layup technique, an epoxy needs to have very special properties; i.e. a reasonably low viscosity, a reasonable pot life, and cure at room temperature. After cure, it should have optimized values for bond strength to glass, peel, shear, tensile and flexural strength, good impact resistance, high glass transition and heat distortion temperatures, etc. It is a fallacy to think that all epoxy resins are the same, or that any epoxy can be used to build a safe, composite airplane. As a licensee of the Rutan Aircraft Factory, we have only approved those epoxy resins which have been tested and approved by the Rutan Aircraft Factory. Since there have been some new developments in epoxy resins since the Cozy 3-place and Cozy Mark IV plans were published, and there might, as a result, be some confusion on the part of new builders as to what epoxy resins are recommended, we thought it would be worth reviewing those epoxies which have been approved:

1. The first epoxy system to be developed for composite construction was the RAE (Rutan Aircraft Epoxy) system (Epolite 2426). It featured either a slow or fast catalyst, which determined both pot-life and rate of cure. It was first produced by Lambert, then by Applied Plastics, and most recently by Hexcel. It is still approved for composite construction.

2. When it was learned that some builders were allergic to the RAE system, Hexcel developed an alternate system which they called Safe-T-Poxy. Its viscosity was a little higher than RAE, so Hexcel modified it to Safe-T-Poxy II (Epolite 2410) by changing the catalyst. It is still approved for composite construction, although OSHA objected to the chemical MDA, which was present in the catalyst in small quantities.

3. While waiting for Hexcel to reformulate, to eliminate the MDA, the Rutan Aircraft Factory tested a number of epoxy resin systems (they said 60) and approved one manufactured by P&W called Aeropoxy (PR2022). Although its physical properties appeared to be quite good, it was difficult to dispense and use in wet layups because of its viscosity. Nevertheless, it is still approved.

4. Hexcel successfully reformulated their Safe-T-Poxy to eliminate MDA and any other chemicals on OSHA's toxicity list, the Rutan Aircraft Factory tested and approved it, and it is available from all of our suppliers. It is called Epolite 2427. We have also tested it. It has very good properties, including a low viscosity, and is highly recommended!

5. The West System is an epoxy system developed by the Gougeon Bros. for boat builders. It is a softer epoxy and recommended for contouring (mixing with micro and spreading over finished layups), because it has excellent adhesion and is much easier to sand. It is not suitable for making glass layups! We were very distressed to hear that one builder was using it for all of his fiberglass layups. It is not approved for layups!


There are quite a few epoxy manufactures that provide good quality epoxy systems that are suitable for structural aircraft parts. Like I first stated, West System is excellent for finishing and is my epoxy of choice for this purpose,,,,but for structural lay-ups I stick with the MGS. I don't think any RV builders are going to fall out of the sky if they used West, but there is better stuff out there more suited for the mission.
 
That dates to early 1994. Any idea what West System resin to which the writer may have referred? I have done a lot of layups with 105 and 205/206 hardeners and found it to be easy to use. Not to say that the MGS product isn't better, but things may have changed, just as they did with the Hexcel resins.
 
Ron here.
Man have i learned alot from you guys. I asked the question and you hit the nail on the head! Its what I'am looking for in variables of opinions. Pro and con. Since my plane is the MOM & POP version ( 9A ) I will continue on the West system because of the tips being filled and feathered at the jogle. Its clear to say that after looking at the examples you have all posted that 403 & 410 would be a safe bet for the construction. If I do venture out into plastic project world there are clearly approved alternatives in epoxy . So here in the northwest 105 and 206 will be mix of choice. (we have had only 4 days this year that it hit 60 Degrees and its 4-22-2011.) I want to thank all of you. 600 hits in 21 hours is pretty good.

Ron in Oregon
 
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Funny. Most A&P schools I know of (including Embry Riddle) use West System epoxy. I asked a similar question at the EAA workshops at OSH last summer and got the same answer. I wonder what changed?

Based on the feedback I've received from numerous trusted people (not Joe Blow the airplane builder), I feel comfortable with West Epoxy in all the applications we require on the RV. And the RV-10 has much more composite work than any other RV.

If I was building a fully composite airplane I would probably choose a different epoxy. I trust WS from a load bearing perspective but I'd probably choose an epoxy that wets out easier and has a TG point that's on the upper end of those available. Especially for those of us in hot weather climates.

Phil
 
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Actually you can use the West System Epoxy for structural use if you use the correct formulation (see below).

I have the plans to the Cozy MK IV have been thorugh all of the info, started work, etc. [NOTE: I'm not sure any of the fiberglass work that we'll be doing is structural so there really should be no problem using even the non-structual west system versions for what we mostly need to do.]

I personally used MGS but a few years ago it changed it's formulation and now must be shipped via hazamat charges (to say nothing of the health warnings on the data sheet).

There's an older but good discussion of epoxies on the canard forum @ http://forum.canardaviation.com/showthread.php?t=3353&highlight=west+epoxy. For those that don't want to read the whole thread I'll post one entry that does a good job of summing up the various epoxies in use (although it's old and the numbers of who is using what aren't current nor are the prices - see below).

Of course this doesn't even get into the Corey Bird method of finishing/filling. A good starting point for that discussion can be found @ http://forum.canardaviation.com/showthread.php?t=1514&highlight=west+epoxy.

The canard forum is a great resource for all things epoxy and canard (of course). BTW, Dan has a good show and tell on his linked post above.


-------------------------------------

thread post of epoxy

What STRUCTURAL epoxy are you using?

In light of the MGS availability issues [during the reformulation of the product supplies were hard to come by] and the changes in hazzardous material classification for MGS, I was wondering if this poll would still have the same results as it did some time back.

When I started my build process, I simply followed Nat Puffer's direct advice on what epoxy to use. So off I went building away using the MGS 335 system. The plans even spell out that MGS L335 is "the system preferred by most builders" due to its properties.

Despite the pathetic amount of progress I have made and some dissatifsaction at my workmanship, I am still at it and working on this project of mine but I await tu fulfillment of my MGS order from the good folks at AS&S.

According to the epoxy poll posted earlier, the majority of us seem to use MGS-285 (22 users) followed by MGS-335 (14 users, including myself.)

10 EZ-Poxy 19.23%
4 Proset 7.69%
22 MGS-285 42.31%
14 MGS-335 26.92%
1 Aeropoxy 1.92%
1 West 1.92%

I suspect that these numbers may be a bit skewed but possibly still representative of the breakdown. I know of one builder, for example, who is using Aeropoxy and recall mention from a few on this list or others. The review that I was given of Aeropoxy was a big thumbs-up. An added benefit is that the manufacturers of Aeropoxy are a USA-based company and local to me. Barring any price or quality disadvantages to a product, I strive to buy American products.

I have tried EZ-Poxy and MGS-335 only. I like the MGS-335 but dislike the way the hardener crystalizes in my environment and with my materials handling. (Hi, my name is Dan and I am an epoxy-pumper and understand that admitting that you have a problem is the first step toward recovery.) Otherwise, I really like the MGS.

The fact that West System is approved for structural use (if you choose the approved forumlas), is widely available, and seems rarely used is a suprise to me. Who is using West (West 105 / 209 Gougeon Bros) for structural use, and what do you think of it?

Checking prices, I found the following numbers after figuring the cost per gallon of mixed resin plus hardener in the appropriate ratios.


My epoxy price breakdown (this post was edited to correct a mathmatical error)

MGS-335 works out to about $93.28/gallon of mixed epoxy+hardener in the appropriate ratio (Aircraft Spruce currently listed prices for 1-gal resin and 1-qt hardener, using the fast hardener).

MGS-285 works out to about $128.64/gallon of mixed epoxy+hardener in the appropriate ratio (Aircraft Spruce currently listed prices for 1-gal resin and 1-qt hardener, using the slow hardener).

West (approved version) works out to about $109.70/gallon of mixed epoxy+hardener in the appropriate ratio (Wicks Aircraft listed prices). Until I actually checked the pricing, I had been under the assumption that West System Epoxy was significantly lower cost.

Aeropoxy large-can quantities works out to about $66.78/gallon of mixed epoxy+hardener in the appropriate ratio (Aircraft Spruce currently listed prices, 5 gallon resin and 2 gallon hardener price). If this is good stuff, as I have heard it is, then Aeropoxy is the most affordable stuff available (of the choices I have checked) at a price of $66.75/gal if you buy in 5-gallon resin quantities. It is worth noting that the low-volume price is slightly higer than the low-volume price of EZpoxy.

Aeropoxy small-can quantities works out to about $88.18/gallon of mixed epoxy+hardener in the appropriate ratio (Aircraft Spruce currently listed prices, 1-quart resin and 1-pint hardener price).

EZ -Poxy works out to about $77.40/gallon of mixed epoxy+hardener in the appropriate ratio. (Aircraft Spruce currently listed prices, 1-gal resin and 0.5-gal hardener price.)

I seem to recall seeing somewhere online a comparison chart and a price breakdown. My numbers are based on mixed-volume in the proper ratios that I was able to extract from the web along with currently listed prices. I did not even begin to consider how shipping, hazzard, poison, tax, and danger-fees figure into the mix, so your results may vary.


Approved Epoxies: From Cozy Mark IV plans, Chapter 3, Page 4:

The following epoxies are approved construction a Mark IV:
RAE is now 4426/9376 fast & 9377 slow
E Z Poxy (formerly Safe-t-Poxy)
Aeropoxy 2032 / 3660 (PTM&W)
West 105 / 209 (Gougeon Bros)
Proset 125 / 239 (Gougeon Bros)
MGS L285 / H285 fast & H287 slow
MGS L335 / H335 fast & H340 slow
The system preferred by most builders is the MGS L335 because of
its excellent properties and the ability to achieve a wide range or cure
times by mixing the fast (15 min.) and slow (6 hrs.) hardners in an
appropriate ratio.

So, what is in your airplane factory?

__________________
Daniel Dillon
Cozy Mark IV #1353 builder (weekends); Semiconductor Field Applications Enginer (weekdays).
Current status as of April '07:
*Chapter 4, 5 - completed
*Chapter 6 - in progres, fuselage assembled without a bottom, step 1 completed.

Continuing to make progress every weekend.

=============================================

Bob
 
WS is great for us

I have used various epoxies and even built a Long EZ using the Rutan recommended ones.

But for RV's the convenience of the west systems and the great surface finish is hard to beat. Nothing we do is structural so the ease of use trumps all structural factors.

The rutan BID glass in conjunction with the 1.7oz cloths for the final ply is a great way to get a smooth strong finish with minimal filler.
Use a hair drier to heat the layups and lower the viscosity so the epoxy will sauturate the weave much faster and be easier to work.
When you are finished with any glass layup or fairing sprinkle it with dry microballooons to soak up any excess and to form a very easy to sand layer that fills minute inperfections and weaves.
 
Ok tuesday 4-19 was the day I put on my elevator tips with the west system. Heres what I did under the direction of you builders and my friends Roy,Kai & Layton.
1) Made sure counterweights installed. Remolded to a thinner profile. Told Vans about it.
2) Sanded whole tip front to back and that it fit well into the counterweight arm.
3) Extra sanding to remove most of the gelco finish. Still white but thinner.
4) drilled #40 holes into fiberglass tip & clecoed all around.
5) comfirmed good fit, YES!
6) Drilled out #40 holes to larger #30 and clecoed. Comfirmed good fit. YES
7) removed all clecos and fiberglass tip.
8) sanded aluminum top and bottom where joggle fits into.
9) dimpled lightly and barely touched hole with a countersink 100*. 120* in the mail.
10) checked every CS4-4 rivet on its fit. All perfectly seated to my standards.
11) pushed two strokes of 105 Resin.....West System into plastic quart container.
12) pushed two strokes of 206 Hardener......"....."...... into same plastic qt. " .
13) stirred for one minute
14) measuring stick 3/4" wide of wood
15) placed a line 1 3/4" from the tip on the stick
16) dipped stick into 403... 1 3/4" deep. Lifted out with tall mound (peaked)
17) mixed a total of 7 mounds of 403.
18) mixed to warm peanut butter spread puddy
19) coated aluminum edges inside horizontal tip 1/2" in.
20) coated fiberglass edge and joggle all the way around the piece
21) pushed on fiberglass tip to horizontal edge.
22) installed pull rivets (CS4-4) every other one.
23) installed rest of rivets.
24) used old credit card to spread oozzzz (Epoxy) over pull rivets & plug mandrel holes.
25) used old credit card (same one) to push ooozzzz (Epoxy) into joggle front to back.
26) used old credit card (same one) removing excess Epoxy and cleaning card with towel
27) Expired defunct bank card (plastic with no apparent residue) will do fine too!
28) Wait 20-24 hours. I can hardly wait!!!!
29) keep stir stick in what left of epoxy mixture in plastic container.
30) tomorrow squeeze bottom of plastic container and cured mixture will pop out in 1 pc.
31) stand and admire your work!!!!Keep standing there and smile!! some more!!!OH YES!
32) sand with 150 or 220 grit its up to you.
33) listen carefully. Got this direct from WEST system yesterday.
34) the filler is 407 West system in your Epoxy mix if you have a dark color paint to finish
35) the filler is 410 West system in your Epoxy mix if you intend to go White or light color
36) going to sleep now! its 4:05am in the morning in Oregon, just got off my night job.
37) let you know (continued) next few days.
38) epoxy still not that sandable, temp down in the fortys durning the night.
39) I cannot stress enough to remove the 403 excess off the surface.One high spot next to impossible to cut down!!!!!!!!!!!!!
40) Will try again tomorrow to sand. I used a airboard sander at 120 lbs.barely touched the high spot from 39)
41) Excess resin poped right out of the plastic quart mixing container on the wooden stick. sorta cool looking art!!!!
42) 48 hours later sanded 403 with 80 grit & 220 sand paper.coming out nicely. hard sanding,glad I removed 403 excess near joggle.
43) I now wish I would have put a patch of 403 in a 8" X 8" square pc of plywood,let set and then sanded the coating to get a feel 4 it!
44) See how strong it is. Lay 2 pcs of plywood flat on plastic sheet.layer the ends & push them together leaving a 1/16" or 1/8" gap
between them, the gap will be made up of your 403 mixture. I was amazed at the strenght! My tips will never come OFF!!!!!
46) Monday, Had to change to 205 hardener. Low in the forty's again. I mixed 2X 205 2x 105 & mixed in 407 to peanut butter putty.
47) Rv builders chimed in. PRO-SEAL tips on. I like this idea too! After all the tip isn't going anywhere with the rivets in it.
48) My putty was a light spread. Sanded down very nice. Recoated tonight on low spots. Filed trailing edge to match elevator.
49) Building HS-910 horizontal tips. Ones in front of the E912 that I glassed in. Van's builder pages 6-9 & 6-10 & 6-11 & 6-13
50) Trimming the HS 910 to fit. 17 times to the belt sander and hand roto-motor tool with a 1/2" diameter grinding wheel. Clecoed in.
51) Maintain a 1/8"th gap between the HS 910 and the E-912 fiberglass pieces. you may have to push in on the tip to expand the sides to match the width on the E-912 tip. Cut a pc of foam to fit in the HS-910. Press a pc against the end to make a impression and cut and trim to fit. This took at least 5 trimmings. I followed Van's Builders page in my 9A book Pgs 6-9 thru 6-13. Once the foam is epoxied in place & cured you can finish top side (the side that faces the counterweight arm and E-912 tip) by wrapping tape around the outside making a little dam where you can now pour a epoxy mixture of 407 or 410 onto that pc of foam. Remember you'll have to maintain that 1/8" clearence when the counterweight arm swings passed it. I used a light filler of 403 to round the inside edge before I used the 407 with a piece of peel ply. When I sand, its always a little bit at a time. I hate trying to fix a fiberglass trimming mistake.
52) once clecoed in check that the two most outer edges match each other again as well as trim as needed to maintain the 1/8" gap.
53) Remove the peel ply. You may keep this finish or add 407 or 410 to finish this inside wall that you just made.
54) Dimple the horizontal aluminum skin and use a countersink on the fiberglass. The CS 4-4 rivets are 120 degree countersink. I used a Stone grit countersink I bought from averytools.com for 1/8"holes. Works great! Did not have to destroy my metal countersink tool.
55) I mixed 205 & 105 with 403 ( 403 Flocked cotton ) and coated the joggle of HS-910 and aluminum skin and installed pull rivets.
56) Removed excess epoxy mixture and pulled and pushed the mixture into the tiny joggle seam. Cleaned off excess 403 mixture.
57) I recommend going to the WEST SYSTEM website and ordering the FREE USER MANUAL. Got mine last Saturday,great publication!
58) I viewed the video shorts on the products and procedures.
59) I did discover a local boat dealer here in town who handles the WEST SYSTEM products. Alan marine 503-399-1161.
60) Buy locally and support your community businesses as well as Averytools and Cleaveland tools,Spruce aircraft,Wicks.Yardstore,Safeair ,Steinair,Brown tool, Aero,Bonaco,aerol.e.d.s. Pac coast avionics.just to name a few.
61) This description of my installation went well with the help of fellow RVer's in my forum question for this installation. I have learned!
62) Many of you who expressed their knowledge of other epoxies I say thanks to you all. Don't think I'll build a composite plane.RV's!!!!
63) From this point on the other fiberglass pieces on the RV tail feathers should come to you as a piece of ART work,like it will for me.
64) If you see a note on your plans,see 6 PP--B-B for details on installation. IT DOES NOT EXIST! not for 9A .Printed courtsey of Van's builders help line.
65) If you have a different idea or procedure or and would like to share it,please do so. I welcome all help in my build project of my MOM & POPS 9A.
66) I want you to all know how I have accomplished all these tasks with all the safety gloves and goggles and do not forget to use whatever it takes to bring you back to your family safely.
67) If I learned one thing it would be to use a paper bowl (non-waxed) to mix my epoxy mixtures. Plastic cup mold is ART after curing but not fun when spreading a new mixture and cannot figure out what these schards of stiff material that stick out of your new spread.
68) Enjoyed sharing and learning.
69) Ron in Oregon.
 
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Rick of Austin said:
But for RV's the convenience of the west systems and the great surface finish is hard to beat. Nothing we do is structural so the ease of use trumps all structural factors.
Click to expand...

Agree....and don't forget the wide cure temperature range.

The 105/209 structural approval in the Cozy literature seems odd. The strength and Tg values published by West are somewhat lower than the other choices in a superficial survey. I might not pick West to build wing spars, but again, the difference means nothing in RV land.

New to homebuilt composites? Do yourself a favor and learn to use the standards; glass microbubbles (little white hollow glass spheres), flox (cotton fiber), fumed silica (aka cabosil).

West physical properties:

http://www.westsystem.com/ss/typical-physical-properties/

Quick one-cup-of-coffee survey (the MGS specs were metric units; hope I got the conversions right):

mjtheq.jpg
 
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Filler Blend

I didn't see this mentioned so far; a couple canard builders have discovered that a 3 to 1 mixture of micro to 410 filler gives a more workable consistency to the filler. Just 25% 410 saves on the premium cost and spreads easier than straight micro.
 
DanH said:
Agree....and don't forget the wide cure temperature range.

The 105/209 structural approval in the Cozy literature seems odd. The strength and Tg values published by West are somewhat lower than the other choices in a superficial survey. I might not pick West to build wing spars, but again, the difference means nothing in RV land.
Click to expand...

Adding to that, a little rooting around looking for info on MGS products turned up specs for 285 & 335 resins. Without elevated temperature cure, the Tg for both products is only a little better than for the West 105/209 combos. Higher for sure, but I would have expected more.

http://www.cozybuilders.org/ref_info/MGS_L285_properties.pdf
http://www.cozybuilders.org/ref_info/MGS_L335_properties.pdf
 
I think you're right Lars. Everybody ignore the Tg entry for MGS in the quick survey chart...I misread the data sheet.
 
WEST SYSTEM EPOXY FOR 9a TAIL FEATHERS

67) If I learned one thing it would be to use a paper bowl (non-waxed) to mix my epoxy mixtures. Plastic cup mold is ART after curing but not fun when spreading a new mixture and cannot figure out what these schards of stiff material that stick out of your new spread.
68) When ordering the West System beginner set start with two cans of Harder. 205 & 206 both are seven oz. Then one can of Resin 105 and it comes in 32oz. Then these next containers are all the same size, 3-1/2" diameter and 7- 1/2" tall. the weights are different. 403 mixture flocked cotton and is 6oz.( structural) . 407 is micro-balloons or micro spheres at 4oz..,a filler used under dark color paint. 410 is 2oz and is a filler under light color paints or white according to West System user manual. 403 is for building a foundation of parts, like cement is to house building. Think of 407 & 410 as what you would use on fiberglass to metal seams on your plane project , like that to finishing plaster coats and seams on walls in a new house. 410 is very easily sanded. Then order the package of West system pumps that pump out the correct ratio of hardner and resin. 410, I liked it as a Great finish coat prior to painting the final color. Ask your Chapter members for ideas.or help. This was all new to me and is how I constructed my tips on my 9A. I thought the RV9A tips came out good. Order your FREE copy of the West System USER MANUAL at Westsystems.com website.
Ron in Oregon. www.westsystem.com
 
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