Oxidised Fibreglass

[BrendAn]

1 minute ago, kgwilson said:

I used a Dulux Industrial 2 pack to paint my aluminium & fibreglass aircraft when I built in in 2015. The paint still looks as good as the day it was done & I've never polished it, just wash it with a car wash & wax.

That's why we love 2k.

I used to paint machines in  industrial enamel. It only lasted a year or 2 before it faded. 

2k was a leap forward when it came out.

[facthunter]

Yeah you wouldn't paint a Prime Mover with anything else. I used ACRAN when it first came out. Nearly as hard as bath tub glazing. I'd HATE to REPAINT a small metal skinned aeroplane that had it on it,  though. You can still get acrylic. My Twin Comanche had it. The Original Paint. Some colours FADE more than others. It's the Pigment. Anything with much RED in it will fade. Nev

[skippydiesel]

I learnt the hard way, if you want to minimise/prevent cracking along seams, etc aircraft paint should have a degree of flex, either inherent or added. I did use flex additive on the glass cowling - all good😈

[skippydiesel]

4 hours ago, BrendAn said:

In the boating world gelcoat is kept polished . Eventually it will wear thin, then it's gets a gelcoat respray or the preferred method these days is paint in 2 Pac epoxy. Lighter than gelcoat and long lasting.

I thought jabirus were painted in Matterhorn white 2 Pac instead of gelcoat.. someone will correct me .

How will it "wear thin" if no abrasives are used/contained within the polish.

 

This is what I was getting at earlier - abrasives, either deliberatly applied or accidentally within the (renovating?) polish WILL steadily remove the paint/gel coat eventually requiring a respray/application at considerable expense, to replace what you did not need to remove - for what?  A temporary ashetetic "buzz".

 

If you must use an abrasive - do it to sell the aircraft - it will still have its gel/paint coating and will come up a treat.

 

I use automotive detergent (in the hope it will do no harm to paint or airframe) rinse off with copious quantities of rain water, dry with synthetic chamois (better, cheaper than natural and kinder on the goats).

When the mood takes me, about 2x/year, I polish with non abrasive polishes.

After "buffing", I reapply the polish to leading edges - do not buff/remove. I hope this will form a sort of sacrificial coating for bugs ie non stick. Far from perfect, seems to work, particularly on prop leading edges and back (worst place for bug contamination). I do my prop more often, to get rid of any persistent bug splatter (comes off with a light spray of water & my chamois) fairly frequently - estimate once per month depending on season 😈

[facthunter]

You only remove the "oxidised" paint. Waxed surfaces protect and make Dirt/bugs etc easier to remove. One thing about bugs is they don't have the guts to do it twice. Little plane were often known as Bugsmashers.  Nev

[turboplanner]

2 hours ago, facthunter said:

You only remove the "oxidised" paint. Waxed surfaces protect and make Dirt/bugs etc easier to remove. One thing about bugs is they don't have the guts to do it twice. Little plane were often known as Bugsmashers.  Nev

Save your breath, we're just doing a lot of thinking for someone who wants an answer but can't be bothered posting a photo or giving the depth. He's already said a fix didn't work at the depth you're talking about and after years of sittinf idle the oxidation is likely to be deep, so well beyond the gelcoat, well into the resin, so better to buy new panels or at the very least pay for an assessment by an FRP expert and I don't mean someone who just owns a similar aircraft.

[facthunter]

Anyhow Sunlight is bad for lots of things especially Paints and Plastics. Moisture is bad for metals. Hangar your Plane if you care for it. nev

[kgwilson]

So if your plane is painted, don't fly during the day and if it is made of metal don't fly it in high humidity fog, mist or rain. Keep it in the hangar and never let it out. Then you can just let it waste away from creeping corrosion, dust, dirt bugs, rats etc.😀

[Underwood]

16 hours ago, turboplanner said:

Save your breath, we're just doing a lot of thinking for someone who wants an answer but can't be bothered posting a photo or giving the depth. He's already said a fix didn't work at the depth you're talking about and after years of sittinf idle the oxidation is likely to be deep, so well beyond the gelcoat, well into the resin, so better to buy new panels or at the very least pay for an assessment by an FRP expert and I don't mean someone who just owns a similar aircraft.

 I do appreciate the replies but didnt specifically reply to you as you seemed to just want to give a lesson on well known aspects of Materials  but no real pertinent advice, sorry if that hurt your feelings.

BTW, I never said it had been sitting idle for years so im a bit confused as to where you got that from.

again everyone thanks for the replies.🙂

[turboplanner]

Still no photo; hmmmm

[facthunter]

GEEZ, KG that's a disappointing reply from a bloke who I reckon has most things pretty together.. Nev

[skippydiesel]

Hi Underwood,

 

Assuming that you have no reason to suspect structural damage due to weathering, it seems to me that you have a couple of choice;

• Just keep it clean, as appearance will likly have little impact on performance. When sale time comes around, use a renovating (abrasive) polish to restore good looks for best presentation/price.
• Use renovating polish now, followed by regular (non abrasive) polishing, to keep aircraft looking "spiffy"
• Use renovating polish on a regular basis (as some have advised) and put $$ away in a saving account for a full respray/re gel coat in a few years time.

 

All the best 😈

 

[facthunter]

I would generally avoid purchasing a resprayed plane  compared to an original finish even if a bit tatty Plane. The first thought about a respray. What is it hiding? Also regarding the Paint stripper. How much is left in the Laps of   riveted seams and how much extra weight has been  added where mass balancing and possible flutter is involved.   Nev

[kgwilson]

1 hour ago, facthunter said:

GEEZ, KG that's a disappointing reply from a bloke who I reckon has most things pretty together.. Nev

It was TIC hence the laughing emojo

[facthunter]

And you've dragged a compliment out of me too.  Nev

[BrendAn]

7 hours ago, Underwood said:

 I do appreciate the replies but didnt specifically reply to you as you seemed to just want to give a lesson on well known aspects of Materials  but no real pertinent advice, sorry if that hurt your feelings.

BTW, I never said it had been sitting idle for years so im a bit confused as to where you got that from.

again everyone thanks for the replies.🙂

We get a bit carried away in here.

Just cut and polish like you said at the start. Finish with a good quality wax.

[skippydiesel]

I am curious about the term Oxidised as used in " Oxidised Fiberglass"

 

Does this really mean that the surface of the composite/gelcoat? has reacted/combined with O2?

 

OR

 

Is it just a descriptor, meaning the surface is dull, may have a powdery texture , some yellowing, all of which may have been caused by some other factor eg UV exposure ?😈

 

 

[facthunter]

The RESIN is the reason..  It's not forever. Nev

[turboplanner]

17 hours ago, facthunter said:

The RESIN is the reason..  It's not forever. Nev

The resin is the critical component and this paper by Sindhu & Joseph gives some data on the subject.

 

There are many resins available and many standards on sale. Whether Oxidation, UV, chemical splashed etc, some products crack or colapse to a powder and the laminate is just a heap of glass fibres and powder. You can see that a lot in cheap boats which have been made with cheap resin and thin laminates.

 

At the other end of the scale are products like these Atkinson FRP Truck Cabs and FRP Refrigerated Vans. There are still plenty in operation after 55 - 59 years. The FRP Refrigerated rigid trucks have had several refrigeration unit replacements and some are on their 7th truck cab/chassis.

 

[skippydiesel]

Hi Turbs,

 

I am impressed by the durability of your FRP examples.

 

I am now more curious;

 

Does the type of "damage" suggest the type/quality of the composite? eg  Jabs out in the weather look a little dull, but seem to be structurally sound.

Can the surface damage be categorised into surface only - indication of deeper problems?

 

With Ninja - I understand that the fuselage is made up of composite panels over an alloy frame, so it's likly that any composite deterioration, is more of an esthetic than a safety issue?

[turboplanner]

36 minutes ago, skippydiesel said:

Hi Turbs,

I am impressed by the durability of your FRP examples.

I am now more curious;

Does the type of "damage" suggest the type/quality of the composite? eg  Jabs out in the weather look a little dull, but seem to be structurally sound.

Yes laminate in high quality resin will retain its memory (springyness) longer.

If you press your thumb against the side of a new Jab, you can do a basic gauge comparison with a similar thickness curved laminate of poor quality resin and your thumb will go in deeper and the material will tank longer to rebound.

36 minutes ago, skippydiesel said:

Can the surface damage be categorised into surface only - indication of deeper problems?

With a gelcoat/polyester/chopped strand mat fibrelass laminate  (very roughly here)

Stage 1 Dull surface of gelcoat (gelcoat problem - polish or cut and polish)

Stage 2 Dull Plus surface powder (as 1 but can be deteriorating in the laminate also)

Stage 3 Tiny cracks, crazing (through the gelcoat ad water getting into the laminate - structural damage starting)

Stage 4 Bigger cracks, big long lines of crazing. When the laminate bulges these cracks open and let the weather in. At the very                least the gelcoat needs sanding off and replaced).

Stage 5 Chunks of gelcoat dropping off between the Stage 4 cracks and crazes, more rapid deterioration of the resin

              and a lot more softening.

Stage 6 Areas of resin crazing into small squares and dropping out of the fibreglass fibres. 

Inspecting for Stages 3,4 you would be doing a lot of thumb pushing.

36 minutes ago, skippydiesel said:

 

With Ninja - I understand that the fuselage is made up of composite panels over an alloy frame, so it's likly that any composite deterioration, is more of an esthetic than a safety issue?

This is where you can't generalise; you have to go back to the individual manufacturer.

They might all be using fibreglass but the engineering, specifications etc will all be different.

 

When the weather has got into the laminate, a monocoque structure is virtually at the point where you have to throw it away.

 

Even with a space frame for structural strength deteriorated panels will be torn off their mountings or collapse in wind pressure, so space frame aircraft can be just as dangerous.

 

Bottom line is you have to replace  deteriorated panels before they become a safety hazard, so you will be needing expert advice from the manufacturer.