What's the best rust protection/underbody seal you've used?

[Acuity30]

ACF-50 has this undeserved good reputation IME. I've used it to protect my bike over winter while kept in an un-air conditioned garage between November and March and I still found light pitting in the chrome. I've watched several comparison vids now and Corrosion Block (which is basically USA ACF-50) never performs very well and washes off very easily.
I'm looking for something I can spray/paint on the underside of metal mudguards, in and on frame rails etc. Stuart Fillingham on Youtube likes the Waxoil spray by Jenolite, but he's a bit of a shill so who knows if it's actually good or he's just wed himself out again for the affiliate money.
I used Hammerite with added Waxoyl paint-on underbody seal on a previous car and I wasn't impressed. After about 2 years there was significant rust forming all over the areas I applied it. It was also extremely messy to apply and a nightmare to clean off unwanted areas.

[ChocolateFrog]

Bilt Hamber.

Dynax UC. It won't wash off though, atleast not easily like ACF-50.

[Acuity30]

ChocolateFrog said:

Bilt Hamber.

Dynax UC. It won't wash off though, atleast not easily like ACF-50.

I'm a huge BH fanboy. Everything I've had off them has worked flawlessly. Neat SurfexHD is a force to be reckoned with. Didn't know they did an underbody seal I'll check it out thanks. I already use their snowfoam, shampoo and DSW

[carinaman]

Have a look at:

https://www.youtube.com/watch?v=R5LSxpoqcWo

I collected my previous bike Xmas 2017. I asked the dealer to ACF-50 it. I think for the following two years I used XCP. I caked the bike in it and did slight damage to finishes trying to remove it in spring. I think it's like aerosol Waxoyl. I've bought ACF-50 but yet to use it. The aerosol can may well have gone flat. My bike was looking good in the showroom after I PXd it in 2023. I think one year I didn't use either but the bike had light use over winter.

I wonder if the sheep's wool oil Lanoil sprays would be any good?

[trickywoo]

I’ve had good results with XCP rust blocker. Much better than acf.

[itcaptainslow]

ChocolateFrog said:

Bilt Hamber.

Dynax UC. It won't wash off though, atleast not easily like ACF-50.

This. Dynax UC is brilliant - dries see through, and I applied it to my daily drive Up! when it was new three years ago. The rear suspension beam bolts for instance, still have their zinc coating and look new.

[PT1984]

I dislike using solvents. Mandatory on discs. But would neat Surfex work on chains?

[trickywoo]

PT1984 said:

I dislike using solvents. Mandatory on discs. But would neat Surfex work on chains?

Works a treat and as it’s water soluble it washes clean. Some people will get jumpy about it getting past the o rings but I don’t think it’s a worry.

[KTMsm]

In fairness one product does not do it all

Dinitrol and Bilt Hamber have an excellent reputation in the classic car world

I have used Waxoyl as one of my Father's classic mechanics highly recommended it - if you used it as recommended, clean it, rust kill it and then put it on, it works well and has done for many years

Lanoguard is the new wonder product - because it's 'natural' but it's awful and needs to be renewed every year - may as well spray old engine oil on

[ChocolateFrog]

KTMsm said:

Lanoguard is the new wonder product - because it's 'natural' but it's awful and needs to be renewed every year - may as well spray old engine oil on

I've never seen an advert for a Bilt Hamber product whereas every second advert I see on social media is for Lanoguard.

Tells me everything I need to know.

[moanthebairns]

Acuity30 said:

ACF-50 has this undeserved good reputation IME. I've used it to protect my bike over winter while kept in an un-air conditioned garage between November and March and I still found light pitting in the chrome. I've watched several comparison vids now and Corrosion Block (which is basically USA ACF-50) never performs very well and washes off very easily.
I'm looking for something I can spray/paint on the underside of metal mudguards, in and on frame rails etc. Stuart Fillingham on Youtube likes the Waxoil spray by Jenolite, but he's a bit of a shill so who knows if it's actually good or he's just wed himself out again for the affiliate money.
I used Hammerite with added Waxoyl paint-on underbody seal on a previous car and I wasn't impressed. After about 2 years there was significant rust forming all over the areas I applied it. It was also extremely messy to apply and a nightmare to clean off unwanted areas.

Do you have power in the garage, can you run a dehumidifier? I've one I got from Argos years ago to dry the washing in my old flat, I use this in the winter. Costs a fking fortune these days mind you.

[hiccy18]

trickywoo said:

I’ve had good results with XCP rust blocker. Much better than acf.

I'll second this.

[Speed addicted]

hiccy18 said:

trickywoo said:

I’ve had good results with XCP rust blocker. Much better than acf.

I'll second this.

I’ve been using ACF50 for years to protect the bikes with good results as long as it’s regularly applied. XCP is more like a spray wax and much harder to remove. I’ve started using it on the parts that get more direct spray..

I tried using lanoguard on the truck chassis last year. Applied in summer with no sign of it after a Scottish winter.
Might try used oil this year.

Edited by Speed addicted on Monday 9th September 21:49

[Biker9090]

As much as I hate to recommend them Bennets Bike Social did a big test and XCP pissed all over the others.

[KTMsm]

Speed addicted said:

I tried using lanoguard on the truck chassis last year. Applied in summer with no sign of it after a Scottish winter.

Might try used oil this year.

All the old farmers and lorry mechanics used to mix old engine oil with axle grease and spray it on their tractor and lorry chassis with a schutz gun every autumn

Works pretty well, stops squeaks and rattles, costs next to nothing but isn't exactly environmentally friendly