Is patching cracked interior of messenger bag a good idea?

I'd take it to a fabric store, find an old lady that looks like she has been sewing all her life and get some real professional advice. They probably have exactly what you need.

https://www.whitemountain.com.au/informa...

My Timbuk2 messenger bagʻs TPU inner liner also started peeling. The above link is for repair of delamination of the TPU/PU waterproof coating on bags, tents, and other waterproofed fabric. The link is the best instruction I found for DIY repair of the waterproofing on your bag. I just tried the iron, two sheets of paper method and it did heat up the TPU/PU waterproof lining well and caused it to stick back to the real fabric underneath. I now need silicon or Teflon spray to stop the TPU lining from peeling in those certain areas. Good luck everyone. Save your bag instead of throwing it away or getting rid of it. The bag is a good bag, in my opinion. Itʻs solid. BUT the waterproof lining is a defect and Timbuk2 doesnʻt want to blatantly admit itʻs their fault. Their Lifetime Warranty IS NOT a real lifetime warranty. It has multiple stipulations and restrictions that it will cover, and it will NOT cover TPU waterproof lining replacement at all. Iʻve read another post about someoneʻs TPU lining peeling or flaking off and he sent it in (Timbuk2 usually requires $25 repair—in my opinion thatʻs not “Lifetime Warranty”), and he got his strap fixed, but they sent him a store credit for the original price of the bag. To me, Timbuk2 is NOT a reputable company. They cut corners on their quality, especially when their bags are priced at the top end of the market. Try the DIY option in the upper link. And please tell others to NOT buy Timbuk2 with TPU waterproofing, or at least inquire the company directly on their most recent Lifetime Warranty policy on their TPU waterproofing lining specifically.

You can absolutely patch the TPU liner to keep the water resistant. Additionally, Timbuk2 offers paid repairs to replace the TPU liner.

I think they'll fix this for $25.00

https://www.timbuk2.com/%2425-repair-fee...

I’ve found that contact cement works very well. lay it on and let it dry for 24 hours

I read about heating the liner to get it to re-adhere to the fabric. I was not successful with this approach did not get consistent results. I finally scraped off the remaining loose liner then applied multiple coats of spray on waterproofing. This is not ideal, but the bag continues to be useable without shedding TPU.

I know this is a really old post, but it was at the top of my search results when I google for why Timbuk2 didn't consider a peeling liner to be covered under their warranty. It cost me $27 to ship the bag to them for inspection, and will cost another $25 to get it repaired and returned. I plan to pay it, and to never buy another bag from Timbuk2 again. I prefer to spend my money with companies that take their own warranties seriously.